Cape Verde and Sugar Cane Juice Rum Categories

I finally finished Arroyo’s Studies on Rum and thought it was really inspiring (I will upload my copy when I get a chance to optimize the PDF). I aim to give an in depth optimistic and pessimistic review of his work soon, but I’m a bit busy and might build up to it as I do more background research.

One thing that caught my eye towards the end of the book was Arroyo’s explanation of sugar cane juice rum categories that we just don’t seem to recognize anymore. This was the difference between defacated & clarified rums versus raw and pure types. Arroyo was an advocate for clarifying sugar cane juice, observing that it’s rums matured faster, while I am an advocate for the raw state or at least celebrating both. Martinique would be a prime example of a defacated and clarified style while Cape Verde would be an example of the raw style. If these were Chardonnays, Martinique would be something a banker would prize out of California and a Cape Verdean grogue would be something garagiste & cult out of Burgundy.

Let me see if I can find Arroyo’s own language, It starts on page 171 in the chapter on Rum Aroma:

[…], a raw sugar cane juice will produce a raw rum quite different in aromatic tone to that of defecated and clarified juice. The rum produced by the raw sugar cane juice will be much richer in the makeup of its Non-Alcohol-Number than that obtained from the defecated and clarified juice. Hence raw cane juice will tend to produce a “heavy” type of rum, while defecated and clarified cane juice will tend to produce a very light type of rum.

Our experiments dealing with sugar cane juice rums have demonstrated that:

(1) The rums produced from raw cane juice are more aromatic, but the aroma lacks the finesse of those produced from defecated and clarified sugar cane juice. These rums also will take a longer period of ageing to reach maturity. When the organoleptic tests from aroma are applied to a sample of this type of rum, it gives the impression that a blend of various rums rather than a single one is being tested; in a word, the rum aroma lacks stability and uniformity, being also rather pungent.

(2) The rums obtained from pasteurized sugar cane juices, but not clarified, occupy an intermediate position with respect to the quality of the aromatic gama. Their aroma is more uniform, stable, suave and delicate. It possesses a more harmonious blend of the different components. Complexity of aroma may be present, but it is stable; and presents a single aromatic effect.

(3) The rums produced from the defecated and clarified sugar cane juice have the same general characteristics as those produced in the same case of pasteurized cane juice; but they possess, besides, greater amplitude and penetration of aroma. Certain tinge of the peculiar odor of matured rums may also be observed in the bouquet of these particular products.

The natural aromatic constituents present in the raw materials used will become another important factor in the bouquet of the resulting rum. In this particular we have that different varieties of sugar cane yield juices with different classes and amounts of aroma. Also in a given cane variety, the aromatic tone will differ according to state of maturity, time elapsed between cutting and grinding the cane, whether burned or fresh cane is cut and ground, etc. etc.

Wow. What beautiful language and he never says that word balanced that I abhor. You can sense Arroyo really grapples with language to meet you on the same plane of experience. He gives us uniformity, which is the language of space, stability which is temporal, suavity which is more abstract, cultural, and definitely reflecting his Spanish stance (#phenomenology). There is harmony, amplitude, and tone which are most commonly the language of sound and music. Arroyo uses tinge which refers to a grappling with scale (remember my obsessions with the scaler adjective problem?). Arroyo’s language is really refreshing and lot of my first collecting projects were to look for evidence of unique language used by producers to convey sensory experiences.

I identify with this Arroyo guy because he is also tuned into metaphor in a way others aren’t yet. In a few paragraphs he also shows us we know near nothing about rum. All the rum talk of the recent renaissance is bunk (but hopefully that is liberating and leaves you optimistic).

Arroyo’s words also defy my Chardonnay analogy and sort of challenge notions of manipulation relative to terroir, but I am standing my ground as an advocate for Cape Verde as producer of the greatest fresh sugar cane juice rums of the world. I originally saw that pungency as a sense of place, though now I know it is mostly a matter of technique (though it is likely the last place to use the technique!). I even speculated that it may have gotten there by not fermenting the beers to dryness and thus getting an exaggerated ratio of aroma to alcohol (a la mosto verde Pisco), but now I know I’m wrong. Whatever it was, its low frequency of occurrence among the rums of the world really captured my attention.

But those aromas, that lack of uniformity, and over the top pungency take on rich cultural symbolism. It is all very similar conceptually to Mezcal, it is hearty like a home cooked meal and so often that beats carefully composed restaurant food. There are no regrets or missed opportunities in the heads & tales cuts, but those aromas are wild. We could also find a word that would be in the same category of suavity, but it would mean something quite different. I bet the Cape Verdean dialect of Portuguese has a word readily available, you probably use your hands as you say it.

Cape Verdean life is no picnic and hard work is done by hand infusing itself into the spirit. The cane is ground by hand power with a trapiche. The music of Cape Verde, the mornas, popularized by Cesária Evora, originally moved to the slow beat of the trapiche. This poor country where everybody lends a hand pushing the trapiche has no continuous super centrifuge of Arroyo. The fires of the still are tended to by hand, fueled by cane bagasse and the temperature is maintained by intuition coupled with watching the flow out of the wooden condenser.

Romance is wonderful, but some of these spirits can slum it a little too much and wind up with taint from copper corrosion due to not nearly enough condensing power or the lack of stainless steel that much of the distilling world has gravitated towards for condensers to reduce ethyl carbamate as well as copper salts. University research papers that cover grogue, and draw comparisons to Cachaca, pretty much only dwell on condensing issues related to quality.

Not all of Cape Verdean production is so rustic and I suspect some of the rums that I love the best, such as Vale d’Paul and Joao Monteiro, are produced in facilities that are relatively more modern. As I checked for spelling, I found some vintage egullet talk on the grogue subject worth browsing.

Not everyone quickly regards the Cape Verdean rums like I do, but how does that change as you’ve come to appreciate Mezcal or learned how it is fermented in the truly raw state unlike the centrifuged, clarified and defecated spirits of Martinique?

Cape Verde still has a lore that much of the rum world has come to lack (on its surface). There never was a sugar cane industry in Cape Verde. Sugar Cane was a failed experiment and became a backyard crop which has to be grown with extreme sensitivity because of the desertification that afflicts much of Cape Verdean agriculture. Rum production goes back centuries but it was completely illegal for much of that time and thus could be seen as the greatest moonshining tradition of the world (second only to the Medronhos of the Al Garve).

The last time I sat down to talk grogue with a producer’s son I was told of an amazing heritage. The head distiller of Vale d’Paul is in his nineties and has distilled his entire life. He has even recognized plots within his own property that produce the best cane for rum making and he sets them aside for himself. At the end of this recent post, there was a telling of terroir recognition among Sri Lankan Arracks, and it no doubt also exists in cane juice rums though we as imbibers have not matured enough to create a demand for it. I’m dying to taste those single plots of Vale d’Paul.

Should we launch a kick starter to buy Cape Verde some Swiss Alfa Laval continuous centrifuges or should we embrace them as they are and hear their story of undisrupted rum production?

Is Cape Verde the living link to rum production of the 19th and early 20th century?

New non-molasses producers are entering the fray, but do they truly know how to sculpt rum? (I am always for sale by the way, and I’m still keeping a lot of secrets from you all.)

We have a long way to go and a lot to see, I have a feeling drinking rum will keep getting better and better.

[Where do we go next? Astute reader, David Wondrich, was quick to point out that many Brazilian cachaças are produced unfiltered & defecated yet do not have defining characteristics found in Cape Verdean rums. So how do we explain that? It has long perplexed me that cachaças don’t share more characteristics in common with Martinique rhums and I’m just beginning to find explanations for that as well.

If we backtrack to Arroyo for a minute:

Also in a given cane variety, the aromatic tone will differ according to state of maturity, time elapsed between cutting and grinding the cane, whether burned or fresh cane is cut and ground, etc. etc.

Some of these ideas are relevant and of course we know they matter in theory, but what we don’t know is the very specifics of how things differ practice. We also latch on to ideas like cane variety or the type of still used and too often ignore specifics of fermentation yet I suspect that is where the most salient aspects of differentiation come into play. I’d like to think I’m well versed in fermentation and most importantly, comparative fermentation, but I’ve put off writing about it for quite some time. Slowly I’ll tackle fermentation options. I’m itching to tackle some yeast and bacteria topics, but I’m waiting for consulting project to materialize a little further.]

Rum, Mitogenic Radiation & The Bio-photon

[Preface: This is a controversial subject and most scientists are extremely skeptical. Bio-photonic concepts are very abstract so it is hard to believe in them, but I intent to explore some of the ideas first hand by recreating Arroyo’s experiments. I would love to get the results Arroyo got whether they can be attributed to mitogenic radiation or not. I’ll never been in a position to pinpoint anything, but it will just raise curiosity and be fun. At this point I think I believe that mitogenic radiation is possible, but that the results are simply not always positive or the relationship is very weak. In many experimental examples the effect is a negative so there is no easy cure-all. It sort of reminds me of the olfactory hallucination idea. Most people are not capable of spotting them when they are harmonious because they do not raise the same kind of flag as when they are inharmonious. When they are already difficult to spot, this makes everything twice as difficult. I just got some papers from the skeptics camp and hopefully I can incorporate their ideas in here in a few days.]

What the hell is mitogenic radiation and what does it have to do with rum fermentation? Rafael Arroyo has a chapter on the subject within his 1945 opus, Studies on Rum, but for some reason wine, beer, and basically no one else is even aware of it. Oh, this is an interesting one.

Mitogenic radiation is an older term relating to the field of bio photonics which is some of the freshest, most controversial science out there and may re-write a lot of what we know about biology in general as well as specifics regarding the very origins of life. It is very fitting that it would be applied to rum first, because as I spelled out recently, rum is by leaps and bounds the most progressive spirit.

A bio photon is light emitted by organisms and even some things not quite alive. It allows physical rather then chemical communication between organisms which can often bring them into strange synchronous states. To cut to the chase in regards to rum, Arroyo was attempting fermentations of simultaneous pure cultures of bacteria & yeast to produce very heavy Jamaica-type rums and repeatably getting amazing results that upended every rule of thumb of fermentation science. When fermentation science says these cultures should compete for resources and inhibit each other, bacteria was making the yeast grow faster and ferment significantly quicker. But was it chemical or physical?

Arroyo had a serious ear to the ground for an agricultural scientist working on a tiny island pre WWII. He was aware of ideas in mitogenic radiation though he knew they were controversial and should be approached with skepticism. Arroyo tried many experiments to prove that no chemical products of the bacteria’s metabolism turbo charged the yeast, but rather that it was light based. The final experiment was fermenting pure cultures separated by a quartz barrier (cylinder within a cylinder) so that they were chemically separate but physically in visual contact and he observed the same results of the yeasts synchronizing with the bacteria. Arroyo was confirming controversial ideas in mitogenic radiation and applying them to a commercial product.

When I tried to find a primer of the subject, the best was written by Stanford scientist Cody Jones and for some reason hosted by Linden Larouche, possibly because it touches on cosmic radiation which relates to plans for colonizing space. It is a wonderful read, but I was left wondering how it got associated with a fringe political group. Jones has an interview on a Larouche news program that begins with political insanity and ends presenting him as a finely articulate speaker. Other pursuits of the subject also brushed up against political weirdness.

After reading Cody Jones’ primer I was reminded of an intriguing Scientific American article from last year, describing the work of Jeremy England at M.I.T., and it turned out to ground everything in some serious respectability. England has been looking at the very origins of life before it grows to anything described by Darwin. At the earliest points there is significant grey area between what is alive and what isn’t and bio photons are still important. They give seemingly non-living or abiotic things the power to organize themselves. This is sort of like a gravity that constantly moves towards life.

It is probably useful to cover some classic experiments to get a better handle on things and all of them are paraphrased by Cody Jones. The first person to recognize the bio photon was Alexander Gurwitsch and the first experiment was performed on onions in 1923.

It is demonstrated that cell mitosis can be induced in an onion stem via extremely low-intensity ultraviolet (UV) emissions from the root of another onion—is that chromatin (as in chromosomes, DNA) is the source of this biological radiation, measured by him in the UV range, and that this radiation stimulates and regulates the mitosis of other cells. In other words, UV radiation emanating from one cell can trigger the act of mitosis in another cell.

This really makes you wonder if we see any of this in agriculture. Many planting decisions are based on competition for chemical resources and designing experiments to isolate the effect of bio photons may prove near impossible. But there are murmurs of cosmo-culture techniques used in wine making and when you consider the possible effects of cosmic radiation on cell function, they might not be so silly.

I found this experiment described by Cody Jones interesting because it dealt specifically with yeast:

Other studies were done on the influence of non-thermal microwaves on the growth rate of yeast cells, were it was found that the effect of either enhanced growth, no effect, or deteriorated growth rate, occurred in repeated studies at very specific frequencies. A significant difference of effect was demonstrated in a narrow microwave range around 42GHz (109 Hz), with a maximum increase in growth rates, relative to a baseline growth rate, occurring at 41.782 GHz and maximum decreased growth rates occurring at the 41.788 GHz. Interestingly, when the applied frequency range was doubled (from 42 to 84GHz range), the new frequency that corresponded to the maximum growth rate was double that of the maximum growth frequency of the previous tests (from 41.782 GHz to 83.564 GHz). These results again demonstrate a highly tuned quality of interaction of radiation with living processes, with fundamental differences of effect occurring within a very narrow range of frequency, as well as a periodicity of effects within a broader range of radiation quality (i.e. microwave), as seen with the growth effect occurring at doubled frequencies.

Not all effects are positive and synchronous effects as seen here can sometimes be damaging.

Here is a great one:

One such experiment done with unicellular flagellate protists, know as dinoflagellates, demonstrated that when two different groups of the protists were brought into optical contact with each other, though still physically separated by quartz containers, they would start to engage in synchronous bio-luminescent flickering among members of the the two different samples, whereas when in non-optical contact, the relationship of the flickering was random.

There is lots of interest in bio photons and cancer, both for detection and therapies:

In another experiment, tests were done on the delayed luminescence from stimulated liver cells, of both the healthy and tumorous variety. It was found that as you increase the density of the healthy tissue, the rate of luminescence increased up to a maximum, at which point it started to decrease with further density increase, whereas with the tumor tissue there was a steady hyperbolic increase in rate of luminosity which continued irrespective of how dense the population of cells became. This was interpreted, in light of Gurwitsch’s work on the role of bio-photon emission in stimulating cell mitosis, as a breakdown in a regulatory function in the tumor tissue, which did not occur in the healthy tissue.

A wildly interesting one:

It is worth mentioning another series of experiments which show similar types of effects conducted by A.B. Burlakov, a Russian scientist following in the Gurwitsch tradition, who looked at the effect of optical contact between fish eggs of differing ages. What he found was that if a group of young eggs was brought into contact with another group just slightly older, the younger group actually accelerated its growth rate as if to catch up, whereas if the difference was of a greater interval, past a certain threshold, the effect was deleterious, resulting in mutations and higher death rates.

And the finale:

We can add to the list of experimental phenomena that orient towards understanding the radiation expression of life, the work currently being done by Dr. Luc Montagnier, the discoverer of the HIV virus. What he has demonstrated is that microscopic fragments of the DNA of various viruses and bacteria in highly dilute solution produce detectable electromagnetic waves, even when the DNA fragments are so minute that they are undetectable by any other means. In one experiment, his lab set up a container of pure water that was in close proximity to a dilute solution that was emitting the measurable electromagnetic waves, but was not in material contact with it. When constituent genetic material (nucleotides, primers, polymerase) was add to the pure water solution there was a synthesis of DNA strands of the same sequence as that which was in the initial dilute solution. The electromagnetic waves of the solution produced in the pure water a characteristic shaped living space, that, when material was added, took the form of that shaped field. We see this as not only the role of radiation in living processes, but this brings into question we actually draw the bounds of what we consider the living substance: clearly in this case it extends far beyond what is conventionally recognized as living material.

This was the experiment that I saw most relevant to the work of Jeremy English as described in Scientific American. I would love to know if this work has been duplicated.

If you’ve got the time, another wonderful primer was written by Compton Rom Bada. The most important ideas within is that there are diseases symptomatic of a loss of coherent light (chaos) like cancer while there are diseases from too much coherent light like Multiple Schlerosis (order) where cells are too in sync with others of different functions which prevent the cells from acting as individuals and performing their own special functions. The take away here is that even if you believe in bio-photonic effect, its no easy positive.

The idea of chaos is very important to concepts important to wine like terroir. It is interesting to speculate how synchrony from bio photons may cause a ripple of order through the chaos, but it is also very hard to tease out anything confidently. A metaphor that I like to use for techniques wine makers and distillers use is to create and frame windows for chaos. There are things we can control and things we cannot that are left to happen chaotically within certain bounds. The inverse now looks true with mitogenic radiation where distillers can frame windows for synchrony, but it will still resemble chaos.

Mitogenic radiation and synchronizing a yeast culture with a bacterial culture is at the heart of Rafael Arroyo’s technique for creating heavy rums. Arroyo also started to classify heavy rums by the dominant auxiliary culture. Jamaica-type heavy rums were created by a fission yeast culture partnered with Clostridium Sacharo Butyricum, but the others did not parallel established traditions. With molasses, Arroyo also explored Propionobacterium Technicum and with fresh sugar cane juice, the Imperfecti mold Oidium Suaveolens, “isolated by the writer from the sap of a tree much used in Puerto Rico for shading coffee plantations.” Um, wow. Anyone know what that tree may be?

What on the market specifically can be tied to any of these ideas?

Fake aging is pointless if the ferments aren’t epic, helping us tease out ideas related to the birth of all life, and emitting bio photons left and right. Can bourbon do any of that? My infatuation with rum just grew again. If its lore, its lore, but its pretty good lore.

Excise Anecdotes from Arrack Country

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These anecdotes have been taken from a wonderful 1983 document written by J.P. Rupasinghe presented at a 1981 symposium on palm sap products.

It starts with acknowledgement of a checkered history, there is a tale of fraud, later a gargantuan tragedy, and an ending with revelations of terroir. If this is the first tale from this vantage point I’ve ever found, are others likely to be equally so good?

Some Anecdotes

I would now wish to relate some anecdotes in my 30 years of experience as an excise officer in the checkered history of the excise department. As a young Superintendent of Excise on first appointment, working in Jaffna, living with another officer who now is Head of another department I have something interesting to say. My colleague was used to take a bottle of fresh toddy in the morning instead of his bed-tea as in his opinion it was more invigorating than the tea. Tasting palmyrah toddy especially during week ends was a passtime and was real fun. The best palmyrah toddy that we had encountered in the Jaffna District and its neighbouring Island was found in the villages of Keerimalai and Senthan Kulam in the Kankesanturai area. The sap from the male palmyrah tree in these areas far excelled any other toddy found in the Jaffna district. I feel the strain of the palmyrah trees found therein and the soil and climatic factors matter in bringing about this condition in toddy. When I came soon afterwards from Jaffna in charge of the State Distillery at Seeduwa there was an Asst. Government Analyst on loan to this department for brief period of 2 years at a time. However, the toddy supplies to the State Distilleries at Seeduwa were obtained from contractors who had their topes in the Chilaw area and they were paid on the pure toddy (alcohol) content of 7.5 % on the gallonage supplied depending on the strength of toddy supplied as indicated by the Ebulliometer test conducted by our officers located at the distillery. It was found that large quantities of toddy received had reached the final stage of fermentation and the toddy did not appear genuine. With the collaboration of the Govt. Analyst at the distillery a random test check was done on suspicion for the presence of starch as there was a rumour that boiled rice water was used in preparing this synthetic toddy. One application of this starch test the results were startling and positive. Starch being not a component of toddy the next obvious thing we had to do was to roll the barrels down the drain leading to Dandugan Oya near-by, to find most of the distillery employees were happily waiting at the far end of the drain away from our sight and having their fill. However this action of destroying such toddy had its desired effects and the problem of synthetic toddy was solved. [They probably used iodine to test for starch.]

When I was at Kalutara thereafter in charge of the large storage and bottling warehouses in the Island I happened to be on leave and the young Superintendent attending to my work had been informed that a large vat containing about 3,000 gallons of over proof arrack was leaking. Perhaps it may have been a simple job for a cooper to stop the leak but this young Superintendent had decided to transfer the arrack to another empty vat near by with the aid of a hand pump. Somehow the operation went on till dusk and the warehouse being newly constructed there were no lights. The hand pump had been used to hard work and suddenly the vat went up in flames, a porter who was on top of the vat hit the warehouse ceiling and fell into the burning vat and must have died instantaneously because what we recovered of him for burial was only his pelvic bone. All attempts to bring down fire was in vain and the balance vat containing overproof arrack, 48 in number, had started bursting like Chinese crackers and a good 100 thousand gallons of overproof arrack was lost in the process. This happened in or around 1957. [Friction from the pump built up intense heat and ignited the high proof spirits.]

Special Arrack

Apart from the severe loss suffered by the department at this stage we were faced with the problem of giving the renters arrack for the taverns they had tendered and a solution had to be found to bridge the gap. This was a time the Gal-Oya and Kantalai Distilleries had ample stocks of rectified, spirits which they were prepared to sell. Samples of rectified spirit and coconut arrack were taken by me to the Government Analyst Department in order to find out a suitable blend for issuing to the public as an alternative to coconut arrack. The Government Analyst Department reported that a blend of 2 of coconut arrack to 1 of rectified spirits would be a satisfactory solution. Thereupon the first such blend was prepared by me at Kalutara and the employees (always hard and inveterate drinkers) were asked to taste and express their opinions. They did so with glee, and that was the birth of what is presently known as Special Arrack or ‘Gal’ Arrack. These proportions are not said to be maintained now and what is put out to the market as special arrack is said to contain more rectified spirit than coconut arrack. The consequences or effects that the consumer of this arrack would have in the long run could be a matter for study. Perhaps the recent census showing a negligible increase in the population may be a result of this.

[When we would assume the special style was developed merely to cut costs, it was actually a response to a catastrophic loss due to a great tragedy. Its easy to miss so many of the stories a spirit can tell.]

Quick Maturation

The late Mr. Mervyn de Silva during his stint of service at the State Distillery experimented with the action of wood shavings on arrack in bottles and on his advice I got a miniature vat constructed, and having placed Halmilla wood shavings, roasted slightly, packed in cylindrical stainless steel wiremesh inserted inside the miniature vat we found that Arrack could be made to mature quickly. A usual 5 year maturation in a vat could be reduced to 2 years by this method. However after we went and took up positions elsewhere in the departments it was found that the few gallons of arrack left in the miniature vat was so good in bouquet and taste that it had an excuse for going fast ”evaporated.” Any how this method is still being used on a large scale at the distillery for quick maturation. [“evaporated” means they enjoyed it so much they drank it, but because they record everything for tax purposes, they wrote it off as evaporated.]


In 1968, I went to France on a French Government Scholarship to study the distillery practices in that country, and I had the good fortune to visit many manufactories in that country. What struck me most was the strain of grapes used to distill Brandy in the Cognac district of France. These grapes unlike the more edible and sweeter grapes in the rest of the country were remarkably sour in taste, and year in year out the same grapes, farmed in that district, were used for the distillation of the more prestigeous Cognacs like ‘Hennessy’ or ‘Remmy Martin’, so much so that the saying goes that ‘a Cognac is a Brandy’ but ‘all Brandies are not Cognacs’. The Armanages, the Salyangnecs, the Polynagcs are all Brandies with distinct flavours produced in specified districts. However, in Sri Lanka we have been slaughter tapping the coconut tree in the tapping belt of Kalutara and allied areas for years. To feed the distilleries therein, the State Distillery has had its supply of toddy year in year out from specific areas. The coconut trees found in these tapping areas are presumably of different strains in as much as ‘Kurumba Water’ taste different from different coconut trees, the sap tapped from the spadices thereof must necessarily be different. I say this as a pointer to those who would like to study this aspect intensively because we are still to find the equivalent of the Cognac district and the particular strains of coconut trees to obtain our toddy to produce a better arrack.

[The strange spellings are all the author’s own. I think one might be a corruption of Salignac, the Cognac house. This passage is wildly profound and it makes you wonder how many people visited Cognac and came back similarly inspired in places we would never suspect. And this was 1981, has their market matured enough since to capture terroir? Can arrack make the jump from commodity to fine? I hope so.

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Rum Comparatively: Understanding Anything Goes

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I’m going to attempt to break some new ground here on comparative understandings of rum. A lot of this is based on new literature I’ve aggressively collected over the past few years. Hopefully I can sway one or two people or at least amuse a few of you.

The opportunity just arose for me to design my own rum at a local distillery that I’ve done consulting work for in the past. It is a long term project and it is allowed to be wildly progressive and possibly fail. The plan is to couple Arroyo’s super fractionated distilling techniques (that is probably my own term) with very old ideas in yeast propagation and fermentation. I want to make a heavy rum of terroir, despite molasses being an international commodity of which I barely have control over. I’m going to bring a sense of place mainly by creating a local foraged fruit starter for wild yeast and using some new ideas in the kinetics of microbial communities to promote a yeast that is seldom dominant to being dominant (there will be other posts on this). We will have light rum, a heavy overproof, and then of course an aged expression which will be a blend of various fragments. There may be room for accelerated aging of some of the fractions very similarly to Lost Spirits projects (perfume industry technique), but I suspect I’ll be maxed out for time before I can get those ideas off the ground. The project will use super fractionated natural aging which is widely practiced, but little understood, or ever a part of discourse so I suspect I will not need anything too exotic to get the results I’m looking for. There is a precedent for everything I aim to do, but what makes it progressive is that it has never been brought to New England or done on such a small scale. I will be deeply diving into distillation history and bringing it all to life.

This rum aims to tell a very New England, very Boston story. It reflects a love for the writings of progressive rum thinkers like those of the Jamaican agricultural experiment station, Harris Eastman Sawyer (the Harvard chemist who I previously identified as the architect of the modern New England rum style in 1900), Rafael Arroyo, the wildly progressive thinker who revolutionized most of the world’s rum production, and the thinkers at the Rum Pilot Plant (I finally found their annotated bibliography). There are many more like Valaer, Amerine, Guymon, Willkie, Murtaugh, Piggot and the student projects at Roseworthy agricultural college. Of course I wouldn’t have come across any of these thinkers without haunting the BPL, M.I.T. and having countless serendipitous Boston conversations.

Another way that it is a Boston story is that I’m personally a big product of Boston wine culture and the pursuit of terroir. The only way the land can shape commodity molasses is by bringing it’s microbial community and what better way to enhance that story by promoting the voice of a seldom seen yeast not harnessed outside of the Caribbean and not in acknowledged use (awesome exceptions keep popping up!) for almost one hundred years (details some other time).

I’ve long wondered why we don’t know more about rum’s actual production. There are a huge amount of practices that go absolutely unnoticed, not yet a part of discourse though other spirits categories like Scotch or Cognac attract a lot of scrutiny. I suspect a lot of it comes down to how much literature we have and a hallmark of my own perspectives and opinions is having a huge amount of literature that other people haven’t seen yet. I’ve slowly been attempting to construct a bibliography of 150 years of rum research with all the citations freely available. It starts with the great Agricola, W.F. Whitehouse in Jamaica reflecting after his distill-off versus the Irish interlopers and ends with the vantage point of L. Fahrasmane and B. Ganou-Parfait in the late 20th century.

There are a lot of glamour issues to why we don’t know more. We often discount the consumer as not ready for it. A brand’s life style image would be tainted by talking too much. Rum is also near always made at such large scales that it just isn’t romantic like a small winery and there aren’t any figures like Randall Grahm speaking articulately of terroir. Progressive producer as celebrity is a very new concept and anyone progressive of yore has been doomed to be ahead of their time. Arroyo wasn’t heralded until decades later and sadly after his death.

Explaining rum can be heavy on the science, especially if we haven’t whittled down the discourse. Of course there is considerable science in the production of any spirit, but rum science is different. For other spirits the science is framed within the confines of production laws, while in rum, anything goes so the science multiplies quickly. Bourbon has one or two templates for production, rum has quite a few and that is why it can tell so many stories. The potential to tell so many stories with rum puts it closer to wine than any other spirit.

These comparative issues make it really hard to learn more about rum. Some rums are made straight forwardly like some batch pot still Bourbons with simple fraction recycling programs. The complete volume of product is aged in barrels just like a Bourbon and when it evaporates it is gone just like Bourbon. When it is bottled it can actually be enjoyed as a single barrel expression with nothing but light filtration and water. This is where the “straight” that we take for granted comes in. For rum to follow nothing but those rules sounds kind of lame to me.

I adore whiskies and brandies made in the classic straight template, but I’m a progressive and often I want something more. It is also not the most efficient and rum production is made in dizzying quantities with global responsibilities connoisseurs can’t seem to grasp. Rum in most cases (but that is changing) is a salvage product so there is a big responsibility to make an affordable product because price moves it more than anything else. More molasses is always piling up. So much of the literature from even the 19th century mentions how on the verge of not viable the sugar cane and rum industry was. If producers were stuck processing staggering volumes under the constraints of a single template consumers could wrap their heads around, there would be problems.

Fierce competition as a commodity and pressure as a salvage product, which has to keep moving, has shaped the logistics of production at various points. Rum producers have basically ended up in scenarios that other spirits producers would never face. A big one is evaporation due to typically being in the tropics. Many islands that were important colonial outposts would ship unaged spirits to Europe to age and avoid costly evaporation while others, typically further south, lacked a welcoming parent and tackled the problem other ways. Before taxes, rum was cheap so a lot of times to keep everything moving on the salvage side, evaporation would just be topped up. This evaporative solera morphed into a classic solera, but that makes it no easier to compare to any other product on the market. The UC Davis algorithm for calculating the average age of solera products does not account for such significant evaporation. This leads to a style of aged product that is hard to wrap your head around, but is delicious. Consumers complain about labels while the products are telling colonial stories we can only access if we read between their words.

For some reason we think of the rum industry as wrought with fraud in manufacturing practices and yet if you study the Rum Pilot Plant or look at the present day World Spirits Conference, the industry is wildly environmentally friendly and energy conscious relative to other large scale industrial processes. They make any new American distillery look like an environmental train wreck. The industry has spectacular responsibilities, both social and environmental, and for the most part it handles them. I don’t want to justify anything, but pressures to adulterate may be pressures to keep product moving during wild swings in consumer tastes. Aspects of the industry are still so slow moving, so antiquated and still stuck in colonial legacies that they cannot turn on a dime. If we interpret the stories correctly, we can put pressure on the industry to change for the positive. Most distilleries are soon to be re-tooled and are set to go post-Kavalan anyhow, and that is something I’ve been meaning to write about in depth.

Another rum template you see a lot of resembles blended scotch whisky. Economical continuous column distilled spirits are blended with small percentages of extra heavy batch pot distilled aged spirit. The pot distilled spirits are a little different than single malts and sometimes they are built like such a brick house they cannot be enjoyed on their own as a single straight expression due to ester contents at levels that would be beyond an acquired taste. Pre Arroyo, there was no category of straight light rum. All light rums were heavier rums blended down with neutral spirits from continuous stills and they were inferior.

Rums made on the blended scotch whisky template have encountered all sorts of quirky economic problems due to political factors such as Reagan and NAFTA, but that era is close to over. Producers did not always bottle their own products for over seas markets and instead mainly sold bulk stocks. Despite the commodity nature of spirits, brands were somehow still important. Consistency was the order of the day and if the client wanted an amount of four year pot still rum for a blend and a producer made too much and now it was aged five year, though it might be more extraordinary, it could just languish in the warehouse. There were also lots of trade restrictions and only so much rum could be sent to Europe so the distilleries were often never producing at capacity, but often slightly over producing relative to what they could export. This led to lots of over aged forgotten rum. Sampling a rare independent bottling will tell you, these forgotten rums could be quite special, but the distilleries had no real protocol for capitalizing on them. Distilleries were often government run or stodgy as hell.

There are many small bottlers currently that seem like their blends are beating the pants off other producers and what they’re really doing is sucking up all those gorgeous odd lots that don’t fit in the high volume commodity-consistency market. As the market for premium rums proves itself, the contracts will expire and producers may bottle formerly speculative premium rums themselves. We fault big producers for being out of touch, but in many cases they may just be waiting for small bottlers to do the high risk dirty work of establishing a premium market.

Many rums take on not so much a Cognac template, which would be double distilled in batch pot stills, but simply Cognac flavor aspirations. An example would be Ron del Barrilitto, a big favorite of mine. Cognac is known for it’s finishing techniques. Caramel is carefully added because re-used barrels do not contribute enough color to converge with the aromas. Boisé, or tannic extracts, are often added because the aroma can be so forceful in one direction that it needs contrast in another to not seem flabby. Sugar is also added typically at the limits of 2% by volume which is 31.56 g/L and as a flavor enhancer it changes the threshold of perception of aromas, amplifying them. These aspirations are much different and much more noble than masking inferior alcohol and appealing to low brow consumers.

The rums of a few producers have an extra technique in their arsenal that has been around so long it is absolutely traditional and that is prune juice (sometimes coupled with spices, but not making it a spiced rum). It is a cousin of 19th century pineapple rum where pineapple juice was added to synthesize the character of mellowed rum. There were no secrets about pineapple rum and it was openly consumed and revered. Prune additive is barely secret. Compounded well, they’re wildly delicious and tell a story of ingenuity, pragmatism, inherited definitions of luxury, and colonial heritage. García Márquez would surely endorse them for the stories they tell.

A progressive belief I have is that aromas in the context of wine & spirits are often illusions or hallucinations and neuroscience is starting to back this up. We don’t describe a wine or spirit itself, but rather our own recollections when we try to describe it. This has tremendous implications for understandings of the terroir concept. We can only bond with a land as expressed through a wine or spirit if we have spent time bonding with other lands. Sensory fragments come at us through aromas tied to color, gustatory and haptic sensations, et al., and we complete them with our recollections (of other lands). Caramel, boisé, and sugar are all ways the land, the producer, and the imbiber sing a song together. In the finest lands there will be three singers.

Among the earliest stories of rum ever is that of caramel color. I’m failing at finding the citation I’m looking for, but basically rum was sold at a price to some imbibers, the same rum was colored with caramel and sold to the same imbibers who gladly paid more. Aromas are bound to color and they should always be partnered with a color that makes them perceived to be the most extraordinary (sometimes this is crystal clarity!). Choosing natural color is the same as coloring, except you decided it was already colored where you wanted it to be. Debates over caramel color put symbolism over sensation in spirits appreciation and takes for granted how flavor is perceived. Just like many connoisseurs do not understand caramel color, not enough produces do either, and many fail to end up with a color systematically tried to be the most extraordinary. On the other hand, many spirits nail it perfectly. The extraordinary is tied to frequency of occurrence and many naturally colored rums stand out at the moment because their frequency of occurrence is currently low.

Rums don’t exactly get reformulated to be cheaper to produce, what happens first is that we drink them all and there is a void to fill. Often rums that catch on and see surges in demand, like Ron Zacapa or Pompero Anniversario, were the product of surpluses. Likely, surpluses of aged rums in both Guatemala and Venezuela were so great that the expressions they put out became so good the market could not deny them. Consumers drank them all and started to complain as they tried to fill the void. A Similar phenomenon happened with Bourbon in the 90’s where bottom shelf bottlings were loaded up with well aged stocks, but we eventually drank them all and the glut was gone. Bourbon consumers have been far more understanding of the changes than fair weather rum fans.

Some times a rum jumps islands such as Zaya as pointed out by CocktailWonk (who this post is in part inspired by). Zaya likely tells a story no one bothers to really translate, but Zaya isn’t supposed to spell it out. Spirits are inadvertently like poetry or painting and the poet is cryptic and ambiguous making you work to find meaning. Zaya was no doubt the product of serious wheelings and dealings as well as a dream of bringing the Caribbean jungle to some opera somewhere. I have a feeling there was a Fitzcarraldo in Zaya and we all missed it. We drank it all and yet it was still ahead of it’s time.

Consumers are asking producers to be the connoisseur for them and that is not how it works, Hemingway would side with me. If anyone needs a template I recommend consulting Hannum and Bloomberg’s Brandies & Liqueurs of the World, (1976). I never wrote about it, but I tracked down Hurst Hannum a few years ago for lunch and was regaled with tales of touring Europe in an MG roadster convertible visiting producers who hadn’t seen a writer since André Simon, and documenting them. They flipped the roadster in front of a Cognac chateau and Gatsby style, the owner righted their car, helped them repair it, and hosted them for a few days. The rum world had Hugh Barty-King and Anton Massel in 1983, but even with the spirits renaissance and distilleries hosting spirits professionals left and right, no truly brilliant connoisseurial investigators have come since.

The last distilling template is the super fractionated template. Spirit from a continuous column stills is taken uncut except for the fusel oil reduced. This is transferred to a batch column still where it is redistilled as slow as possible with high reflux and separated into as few as five fractions. The first fraction is recycled or possibly re-fermented to have it’s aldehydes reduced into ethanol by yeasts (Guymon’s technique) while the remaining fractions go on to become rum. The last fractions, already low in fusel oil, are distilled further along than in the straight Bourbon template to accumulate rum oil. The same continuous still used to produce near neutral spirits can be briefly retooled to participate in this process and that is why Ron del Barrilito can buy un-rectified stocks from other producers. Specialty ferments can likely be lined up in the continuum.

Percentages of each fraction get blended together to be light rum. The remainder of each fraction is not entirely aged as heavy rum. The middle fractions are mostly water and ethanol (congener free) so they do not benefit from aging. The scraps that go into the barrel age faster because there is less unageable ethanol and water taking up space in the barrel. These techniques are practiced with infinite options and it is very hard to say to what degree any specific producers use them.

Super fractionated distilling is practiced in tandem with deeply involved biological control over fermentation. Fermentations are inoculated with more than just a single pure colony of yeast in some cases as well as selected bacterial strains. Unless the heaviest possible rum is desired, bacteria in spontaneous fermentations can eat up sugar, reducing potential alcohol. Arroyo developed methods of inoculating bacteria at later stages in fermentation so a desired yield of alcohol could be produced before bacteria started to metabolize hard to ferment residual sugar or other compounds.

Pursuing economy is not about being cheap, it is mainly about environmental responsibility and each percentage point of potential ethanol squandered is an environmental burden with intense water usage and significant effluent to dispose of and this was even a concern in the 19th century. Spirit production priorities differ from that of wine and the comparative philosophies are something I’ve wanted to tackle in depth for quite some time (there is a lot of literature left on my list to collect).

Large distilleries have economies of scale that allow for scheduling of exotic fermentations because they have shifts running around the clock. Bacteria may be inoculated, then like a bun in the oven, the wash will have to be distilled so many hours later to not spoil. Ron del Barillito may have fermentation dreams that are beyond their ability to staff their own distillery and that is why they purchase stocks from an around-the-clock operation. That is sadly not the sexiest fact to explain to a consumer.

Small distilleries have logistical problems trying to emulate larger operations, but an option that I’m not sure how widely it is used is immobilized cell technology where bacteria or yeast are immobilized in alginate beads. Significant biomass of yeast or bacteria can be put into a fermentation then completely removed using a wire cage arresting the activity of the beads. Specialty fermentations can be designed that fit into the scheduling logistics of a small distillery and that is something I aim to explore.

Progressive ideas, that started with Rafael Arroyo, push rum into the territory of ingestible perfumes and that is the pinnacle of being able to cement and retrieve a memory. Super fractionated aging may even render the techniques of the Lost Spirits distillery unnecessary and irrelevant. Pure culture multiple inoculation biotechnology and super fractioning techniques are in no way cheating and simply represent visionary dreams and possibilities just like those of the perfumer. The contents are hard to label, but the aims are pure.

Many rum production techniques can be portrayed as modern, progressive, and visionary and that is my reading of so many rums, but somehow it gets lost when we are multiple generations removed from Arroyo and other major thinkers. Producers themselves end up in a bubble and lose the ability to contextualize their own product. If you can’t contextualize it you can’t meet the emerging demands of a curious premium consumer. Spirit producers probably need to relearn their own industry’s history.

Hopefully I’ve succeeding in portraying that rums can reflect the social aspects of terroir better than even wine. They are capable of even being pushed out of their home lands as seen with Bacardi in Cuba and again with Zaya. As society and political climate changes so too does rum. When we think rum is unregulated and unconstrained by production laws that is far from the truth.

Now that a lot of trade barriers have come down for rum, one of the most recent regulations to shape it concerns the toxic congener ethyl carbamate. Producers globally are supposed to reduce their levels of ethyl carbamate in spirits and scotch producers have already made strides so great no one noticed. That sounds nice, but compliance domestically is voluntary and many domestic producers have no clue what the hell it even is. When a producer wants to cross borders they must comply and that means new capital investments which are hard to finance. The chemical compound becomes a trade barrier and keeps some producers out of big markets like the U.S.

Instead of successfully becoming a barrier and slowing trade, ethyl carbamate has caused governments like Brazil to reinvest in agricultural research to better control production in general. Ethyl carbamate is reduced by using stills that are strategic combinations of copper and stainless steel (typically a stainless condenser) because it is the product of complex copper reactions. Reflections on technique across the board spurred by ethyl carbamate have improved spirits quality in multiple areas.

Every spirit tells a story of course, but counter intuitively the story a rum tells is less contrived. Scotch and Bourbon producers apply startling science and marketing acumen to lock their spirits in time, dodging risk while rums float around and are free to reflect so much.

We need to get away from an obsession with truth in labeling in all spirit categories. Navigating spirits and wine is a large part of the fun. The challenges are why we can find value. We also live in a new era where photos can be taken of labels then immediately scanned on a smart phone and any dirty secret revealed. Templeton and any other MGP whiskey did nothing but continue the traditional marketing of spirits that paralleled traditional production. Any additional information a consumer needed to be “protected” is a label snapshot away. The government is on top of protecting you from toxic congeners like ethyl carbamate and in turn overly affordable imports from underdeveloped countries.

I hope I’ve done some justice explaining production templates and that they may clarify the tricky proposition of creating labels. Rums made as straight Bourbons will be easier to understand, but they will not be as extraordinary as other more elaborate templates. There is nothing finer than rum as we make it. If rums were labeled as they were made, they’d need bigger labels. The multi dimensionality would not make them easy to compare and in the end we’d just take Anthony Bourdain’s advice and submit while soaking up a story.


Amateur Spirits Analsyis

The home hydrometer test is great place to begin for investigating spirit finishing techniques, especially because it does not require you to sacrifice any samples such as in obscuration tests that distillers are often required to perform to see to what extent soluble solids from barrels obscure the true taxable ethanol of a spirit. For whiskey, in most cases, the barrel obscures 0.2 percentage points. What I often advocate is sacrificing a small sample to a food dehydrator. This could be 50 mL’s measured with a pycnometer. It can be weighed before and after dehydration so see how much non-volatile fraction there is which will be mainly sugar. Often, if there is something like glycerol it will not crystalize and can be seen as a little oil slick. Rum connoisseurs will be surprised to find that they will probably very rarely ever seen glycerol. I’ve only ever found it in gins. Now that you’ve destroyed a sample worth only a few dollars, you can carefully reconstitute it with neutral spirits like vodka to see what the non-volatile fraction tastes like with no volatile fraction to bias it. Often there will be aroma because the bassy notes contributed by a barrel are barely volatile as well as possibly notes contributed by sherry barrels.

A limitation of the hydrometer that comes up from time to time is that if the spirit was bottled under proof accidentally, it will not be caught and sugar will probably be attributed to the culprit whereas dehydration will give different results. I’ve only seen under advertised proof spirits from very new distilleries that have not mastered blending yet.

If curiosity is burning or if you are in a position where it is worth your while to do competitor analysis, you can sacrifice a larger sample to the Micko test which was used more than a century ago to look at adulterated Jamaican rums. Take a genuine sample and the suspected adulterated sample and dilute them to the same proof and volume. Now distill them with identical amounts of very high reflux and distillation times on small scale laboratory glassware. Collect at least five identical fractions. Similar aromas across both samples should be in the same fractions while an adulterant, like orange oil, will stick out like a sore thumb now that it has been concentrated.

The same Micko test can teach new producers the art of cutting and blending. You compare your own product to a role model so you can see more easily how your most volatile and least volatile fractions compare. Many new distillers and new blenders would greatly benefit from this affordable concept. Formal elaborations of the Micko test exist associated with other specific scientists and I aim to touch upon them in depth some day (Arroyo fully elaborated the test).

I have long thought many rums contained artificial vanillin or it was just a product of a style of aging that I really didn’t enjoy (or fully understand), sort of like wines that see too much new oak. Old UC Davis texts describe methods of treating barrel staves with pure oxygen to maximize lignification and if that is the case, all the aromas come from traditional ingredients and traditional chemical processes though sped up in very similar methods to what Lost Spirits is doing. I always thought if manipulation of staves was the case, I would have found a research paper on it outside of the UC Davis work.

I had heard anecdotally long ago that when you buy a sherry, port or sauternes cask, there is an amount of wine sloshing around in it to prevent bacterial growth. Producers would not drain the residual wine but just fill on top of it and who could blame them. Hell, I’d hold it against them if they didn’t. We may be given an illusion that the wine character is merely soaked into the staves, but that may not be the case. These small stories that rums can tell are never in any official literature because it is quasi legal and is only a secret that the barrel men and the drinker are in on.

Some of the distilleries in the Caribbean are among the very largest in the world, but that does not mean over distillation as suggested by CocktailWonk is a problem. When we say distillation at a high proof strips congenerics that makes the assumption that we are making cuts during batch distillation or taking off side streams during continuous distillation. In the Arroyo system of simultaneously making light and heavy spirits, washes are first stripped on a continuous still, cuts are not taken but fusel oil is reduced. That uncut distillate is rectified in batch column stills and distilled extremely slow under very high levels of reflux to divide the spirit into multiple fractions. Percentages of each of those fractions become the straight light rum and then the majority of the rest gets aged in barrels for extended times. Aged product is then blended down with either unique stocks, light rum, or neutral spirits to bring congener thresholds to where they need to be.

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Coconut Research Institute

Papers digitized by the Coconut Research Institute of Sri Lanka are really impressing me. For some reason that part of the world is better at digitizing their agricultural literature than the west. Anyone remember my round up of recent vermouth literature? Most of the papers came from India.

If you really think about it, the hundreds of new spirits producers in this country are getting ripped off these days. This isn’t from the perspective of taxes or investment money, its from the perspective of government funded helpful and pragmatic research directed at their industry (that we used to have, the IRS of all people being the most important). If we aren’t going to do new research, we might as well digitize the old stuff as a service to all these new job creators. It would be cool if the Library of Congress took an interest. In the mean time, you’ve got me.

The Manufacture and Characteristics of Ceylon Arrack—I
The history in here is wildly interesting with spectacular photographs of the tree tappers which give a better understanding of how it all goes down. I love at the end how they use “staybrite” brand scouring pads to filter the coconut sap.

The Commercial Possibilities of Manufacturing High Grade Vinegar from Coconut Toddy
Lately I’ve been collecting vinegar research papers to help a start up producer in Maine that hopes to do some amazing stuff with cider vinegar. This paper isn’t too in depth, but does give a nice overview of the generator method which often a new concept to startup producers.

Microbiology of Coconut Sap Fermentation
This is a really wonderful accessible paper. I’m hoping to start to do very similar projects with a rum I am trying to develop which uses a novel indigenous yeast fermentation technique.

Toddy Effluent from Distilleries
A great easy to understand look at effluent that shows how environmentally conscious they were early on. This pertains to arrack but should be insightful to any spirit producer. The conclusion section is well worth checking out.

The Manufacture of Coconut Toddy Vinegar by the “Generator” Process

The History of Vinegar Production and the Use of Coconut Toddy as a Raw Material: Part I Historical Introduction
Interesting but a bit tedious. What is wild is that the case wasn’t completely crack until into the 20th century.

The History of Vinegar Production and the Use of Coconut Toddy as a Raw Material: Part II

This Pure Products article from 1917 on coconut sap starting on page 285 is wildly interesting. It is a great survey from scientists visiting the area.

The Prior Patents of Rafael Arroyo

So who was this guy, Rafael Arroyo, and why did he win the contract to advance Puerto Rican rum? Could anyone else have done as good a job? Was this guy some sort of genius or coincidentally just a native with the right scientific skill set? (my bet is staggering genius.)

In tracking down his lost papers I found another patent of his. Arroyo is known to most contemporary rum enthusiasts through his patent on producing heavy bodied rums which was digitized by google and thus accessible.

We can get a glimpse of Arroyo’s credentials through his other patents which are all for advanced industrial fermentations proving he entered rum work with a formidable skill set. By the 1940’s when Arroyo was working on rum he must have been well into his career and had some pretty heavy industrial experience under his belt.

Arroyo also appears to be from Puerto Rico which isn’t the biggest surprise, though it is surprising that PR industry was doing boundary pushing work in bio technology in the 1930’s.

Hopefully soon I can dig up an obituary so we can learn more about the guy.

[Added 1/17/15 courtesy awesome reader Rex Clingan]

From the American Chemical Society 1949:
Rafael Arroyo, 57, Puerto Rican industrial research chemist, died suddenly Aug. 16 in Rio Piedras, Puerto Rico. He had been for many years head of the chemistry department of the Agricultural Experiment Station at Rio Piedras, and specialized in the industrial utilization of sugar cane molasses and its by-products. He originated the “Proceso Arroyo” under which the production of rum spirits by a special treatment of the molasses used in the fermentation stage was increased. He graduated in 1916 from Louisiana State University, where he had majored in sugar engineering. In the U. S. he had worked for Armour and Co., Staier Chemical Co., and the U. S. Industrial Alcohol Co. He joined ACS in 1946.

Fermentation Agent 1938

Art of producing butanol and acetone by fermentation of molasses 1938

Culture for butyric acid fermentation 1939

Fermentation process for producing butyric acid 1939

Light reading on Ar(r)ack anyone?

Science Education Series
No. 16
Industries based on alcoholic fermentation in Sri Lanka
by Upali Samarajeewa

I cannot say enough good things about this text (linked above) and it fills in a big chunk of spirits knowledge which is palm sap derived spirits like Arrack. Keep in mind that this is Sri Lanka, the large island off the southern tip of India and not Batavia or Java which come from quite a ways east.

Casual readers will enjoy the mention of products on the market in 1986 and salivate at the prospect of drinking a VSOA (very special old arrack). We learn that one of the reasons the spirits were not exported is that they weren’t even able to produce enough for local markets and that is why some of their araks had to be blended with molasses based rums. Gilbey’s made something called “Captain Cheers”?

Owners of coconut palms in other countries like Jamaica with former very small traditions of making palm sap derived spirits will enjoy the details on cultivation and fermentation. How soon until we see products hit the market from less famous regions? This document will speed that up! I’m available to consult!

Beverage technologists will admire the bibliography and rare bits of information. Educators will admire the organizational skill of the author. The bulletin is designed to be an applied look at science directed at local interests. Lucky for us, the locals are interested in alcoholic spirits!

The PDF is missing at least one page and sadly the bibliography is not intact, but I was able to track down one of the more important papers referenced: Distillation, Maturation and Blending of Arrack by T.D. Ekmon of the State Distilleries Corporation, Seeduwa (1983). It isn’t exactly monumental and the best parts made Samarajeewa’s larger document.

(If the link breaks, I can send the documents to whoever needs it.)

Rafael Arroyo’s Lost Papers on Rum

[I have made a great PDF of a Arroyo’s 1945 Studies on Rum and I’m pleased to say the text has even surpassed my expectations. I’m going to finishing reading it and playing with it then I’ll eventually release it. I need to de-warp some of the page scannings and reduce the size of the PDF because it currently rings in at 60MBs.]

To my knowledge there are no accessible digitized copies of Rafael Arroyo’s 1945 Studies on Rum. I do have a Spanish language edition PDF somewhere, but sadly I do not understand Spanish (hopefully the Spanish version will help check that we have all of the English version).

But what is this all about? Through a grant from the U.S. government Arroyo set out to do detailed studies of rum production and he created new techniques in fermentation that revolutionized how rum was made. Even in Jamaica, which is known for dunder pits and muck holes, the leading producer, Appleton, likely favors the Arroyo method. I’m sure if you’re here, you already know a little about Arroyo.

Not much happened with Arroyo’s work until decades later because of the timing of WWII (this was explained in Rum: Yesterday and Today), but everything was given an update with Puerto Rico’s Rum Pilot Plant and those agricultural bulletins are mostly lost as well. The RPP works are a series of twenty something bulletins and are in both English and Spanish because of how they were funded by the U.S. government. These documents transformed how rum is made around the world and were supposed to be shared and accessible, but somehow they’ve become elusive and even the most serious PhD spirits researchers do not cite them in bibliographies.

I have collected probably all of Arroyo’s citations from the journals they were originally appearing in courtesy the bibliography of the late John E. Murtaugh who was one of the great distillation educators as well as a significant contributing author to the Alcohol Text book.

What I propose is that readers and myself make inter library loan requests for the citations then upload the PDFs so the works will become more accessible. Inter library loan only allows so many requests per person so it will take many individuals to get all the documents in a timely fashion (If you make a request just let readers know which you made in the comments).

Next we will tackle the Rum Pilot Plant bulletins and I have strong leads to their locations. I actually have the entire annotated bibliography of all articles related to the Rum Pilot Plant, but its a pretty big under taking to collect and beyond the scope of most people’s interests.

Arroyo, R. 1941. The manufacture of rum. Sugar

Arroyo, R. 1942. The manufacture of rum. Sugar
37(1), (5), (7). [this and the article above may actually refer to the series below. I think these two citations had typos and the BPL found the correct ones in Sugar below and sent them. The BPL is awesome!]

Arroyo, R. 1941. The manufacture of rum Part I. Sugar

Arroyo, R. 1942. The manufacture of rum Part II. Sugar

Arroyo, R. 1942. The manufacture of rum Part III. Sugar

Arroyo R. 1942 The manufacture of rum Part IV. Sugar

Arroyo R. 1942 The manufacture of rum Part V. Sugar

Arroyo, R. 1942. US Patent 2,295,150. Ethanol Fermentation of Black Strap Molasses.

Arroyo, R. 1945. US Patent 2,386,924. Production of heavy rums.

Arroyo, R. 1945. The production of heavy bodied rum. International Sugar Journal 40(11):34-39.

Arroyo, R. 1945. The production of heavy bodied rum. Sugar, 40:34-39. [Is this the same article from a different journal? I think that this citation is in error so I’m not bothering with it.]

Arroyo, R. 1945. Studies on rum. Research Bulletin
No. 5 (University of Puerto Rico, Agricultural Experiment Station, Rio Piedras, Puerto Rico), December. [I have this but have not shared it!]

Arroyo, R. 1947. The economics of rum production. International Sugar Journal 49:292-294, 325-327. [part I, part II]

Arroyo, R. 1948a. The production of straight light rums from blackstrap. International Sugar Journal 50:150-152.

Arroyo, R. 1948b. The flavour of rum – recent chromatographic research. International Sugar Journal 50:210.

Arroyo, R. 1948c. Simultaneous production of light and heavy rum. International Sugar Journal 50:289-291.

Arroyo, R. 1949a. The Arroyo fermentation process for alcohol and light rum from molasses. Sugar Journal 11(8):5-12.

Arroyo, R. 1949b. A new rum distillation process. Sugar 44 (7):34-36.

Arroyo, R. 1949c. Rum distillery yields and efficiencies factors affecting them. International Sugar Journal 51:163-169, 189-191.

Arroyo, R. 1950. Advanced features in rum fermentation. International Sugar Journal 52:42-44.

Arroyo died in 1949 so a few of these would have published posthumously.

Additional articles of interest:

L’Anson P. 1976. Diversification in the distilleries. Wine and Spirit. 106: 38-39, 42-43, 45.

Kampen, W.H. 1975. Technology of the rum industry. Sugar y Azucar. 36-43

Kampen, W.H. 1975. Technology of the rum industry.
Sugar & Azucar 70(8):36-43. [I can’t remember were I took these two different citations from, but who knows if they are the same article?]

Aguiar, J.L., Rodriguez-Benitez, V., and Garcia Morin, M., 1968, Study of the Use and Reuse of Activated Charcoal in Rum Processing, J. Agr. Univ. P.R. 52(1).

A.C. Simpson, Gin Manufacture, 1966

I thought this paper was so good and so useful I’d retype it so it could be better indexed by google and more easily found. I have one more bulletin of blockbuster importance to write about before I write my annotated bibliography of gin. Amidst the document, I may input my own comments as quotations via the WordPress formatting.

My aim with all these documents is to raise the quality of gin from new producers. Remember, a high tide lifts all boats.

A.C. Simpson, Gin Manufacture. Process Biotechnology, October 1966.

Gin Manufacture
A.C. Simpson, B.Sc. joined W.&A. Gilbey at Harlow, Essex in 1956 as research assistant. In 1961 he was appointed chief chemist with general responsibilities for quality control and wine and spirit bottling.

The key factors in the manufacture of gin are the spirit used, the botanical formulae and the technique of distillation. Unlike whisky, the spirit used for gin should have no indigenous flavour, the taste of the final beverage deriving entirely from the juniper, and other botanicals. The present article, dealing primarily with the manufacture of London dry gin, also points to the differences between this and gins such as Steinhager and Borovicka.

Most of the gin produced and drunk throughout the world is correctly described as London dry gin: the description relates to the process and not the siting of the distillery. Holland’s gin, centred in the town of Schiedam in the Netherlands, is distinct in flavour and method of production. Plymouth gin comes from a unique distillery in Devon. A large quantity of gin is also made, generally for limited local markets, by various compounding and flavouring techniques. It is the manufacture of London dry gin which is specifically described in this article.

The word ‘gin’ is derived from the French ‘geniève’, meaning juniper: it is from this plant that the principal flavouring agent is drawn. Gin is said to have been invented by the Dutchman, Franciscus de la Boe in the seventeenth century, as a specific based on the diuretic properties of juniper oil [1 Encyclopedia Britannica]. Despite a medicinal origin, gin had acquired a reputation in England a century later which was the contrary in extreme. It had become the principal agent of drunkenness among the lower classes and notorious gin shops of the period displayed such enticements as ‘Drunk for 1d, dead drunk for 2d, straw for nothing’. Improvement came about with the retail licensing system and eventual concentration of distillery practice into the hands of a few large companies which developed individual strictly secret formulae. Lately the production of gin has been subject to scientific control in order to maintain uniformity in an essentially batch process.

By definition London dry gin is made from a relatively pure ethyl alcohol, flavoured by redistillation with various plant materials (botanicals) notable for their richness in essential oils. In a classification of spirits, gin is first cousin to liqueur and only distantly related to whisky and brandy, in which the flavour derives from the source of the alcohol.

Compound gin, made by the direct addition of essential oils to the spirit is inferior in quality to distilled gin. The property of dryness in gin is associated with degree of flavour: a very dry gin is distilled from a low proportion o botanicals.

Gin is classified for Excise purposes as British compounded spirit which can be manufactured from immature spirit and distributed to the public without a statutory age.

All spirits are defined for Excise, general trade purposes and retail in terms of percentage of proof spirit, a scale of alcoholic strength linearly proportional to percent ethyl alcohol by volume in which proof spirit has a specific gravity of 0.92308 at 51°F [2]. On this scale, pure ethyl alcohol equals 175.35% proof; and 70% proof, the normal retail strength of spirits is equivalent to 40% by volume at normal temperature. In the parlance of the trade the former strength is 75 op (over proof) and the latter 30 up (under proof).

Gin production demands a supply of rectified fermentation spirit. The spirit much be clean and neutral in taste and odour and contain only traces of aldehydes, esters, fusel oils and other congenerics. The carbohydrate source of the spirit is generally grain (maize) but gin can be made from spirit of any source if it conforms to high analytical standards and is free from contaminant or congeneric odours. Spirit from molasses and, possibly, potato may therefore qualify (in Russia, spirit for vodka comes from these substrates). As the initial production of spirit is not an essential part of gin manufacture many gin distillers are not, themselves, producers of spirit.

This last paragraph is interesting because now there is the emerging idea that you can only be a “craft” distillery if you produce your own neutral spirits even if you probably shouldn’t create the environmental burden.

The basic spirit is made from grain by saccharification of the mash with malted barley and distillation of the fermented mash in a patent still. The methods and materials bear a close relationship with those of the grain whisky industry. A spirit suitable for gin is obtained from Scotch grain whisky by re-rectification.

I wonder what percentage of patent still whiskey production in Scotland is shipped to gin producers. Negligible or greater than 10%?

For the production of alcohol of good organoleptic quality from a fermentation spirit the fusel oils should be removed at the appropriate plate in the rectification column. Neutral alcohol is collected at the highest possible proof.

In North America, grain alcohol of extremely high purity and odour quality is produced in distilleries operating continuous, multi-column stills. Strict attention is paid to the conditions of fermentation, both in temperature control and sterility: the object is to maximize the yield of ethyl alcohol from a given weight of grain. The composition of the mash is regulated to secure good enzymatic conversion without the formation of much fusel oil. The spirit produced is adequate in quality for either gin or vodka manufacture. Some grain spirit made in Britain for gin retains an odour suggestive of its origin, due to incomplete rectification and purification. Many gin distillers who are not spirit manufactures rectify the spirit they buy before distilling it into gin.

It surprised me that they rectified. You’d think as far as energy usage went, it would make more sense to get it done to spec the first time, but maybe the industry was not that organized yet. I think the above paragraph is a shout out to Seagram’s.

The essential botanical of gin is the berry of the European juniper tree, Juniperus communis L; other flavouring agents come from a number of plants including coriander, angelica, orange, cinnamon, nutmeg, cardamom, orris and others. Juniper berries, coriander seeds and angelica root are probably common factors in the composition of all London dry gins but the proportions differ from one distiller to another. The ratio of the three main flavouring agents and the inclusion of other selected botanicals are defined by the distiller’s formula: an original combination which determines the character of gin. Distillers therefore do not disclose their botanical formulae.

Juniper berries [6] for the purposes of gin distillation are grown in Central Europe; the best berries come from the Chianti district of Tuscany but suitable material is also obtainable from Southern Germany and Yugoslavia. Berries from the Tyrol, Hungery and Czechoslavakia are generally utilised for local production of a juniper liqueur. At maturity the berries are smooth skinned, deep blue in colour and 5-8mm diam. Fruiting is biennial and the ripe berries are removed by harvesters who agitate the branches of the trees causing the berries to fall upon sheets laid on the ground. The berries are winnowed and carefully dried avoiding damage and fermentation, and sorted into culinary and industrial grades. The adulteration of berries with those of other species of Juniperus, e.g. oxycedrus is no longer so widespread because collection of the adulterant is no less arduous.

Gin I imagine demands the culinary grade of juniper?

Juniper berries are classified and selected for gin on the basis of appearance and the physical and organoleptic properties of the extracted essential oil (1.5-3.0%). Several components of the oil have been isolated and identified [6-8], by gas chromatographic analysis, Klein and Farrow [9] found 26.5% ∝-pinene, 9.0% myrcene, 8.8% sabinene and 3.8% limonene. It is to be expected that the components and the flavour of the oil will vary with locality and season: these factors are reflected in the physical properties of the oil on which the criteria of selection are based. For gin the berries should not give an oil with a predominantly terpenic odour [10]; the oxygenated compounds, in particular terpinen-4-ol, possess the aromatic flavour which characterises the best berries.

The criticism here of terpenic odor I think is why non communis Junipers are discouraged.

The second major botanical, the fruit of the herbaceous annual Coriandrum sativum [4], is cultivated in Russia, Roumania and other East European countries, for the supply of gin distilleries and the essential oil industry. The crop is also grown in the US, North Africa and surprisingly, in Essex, whence it is available to the English distiller after a good summer. Harvesting coriander demands judgement, for the fruit ripens sequentially and the farmer risks on the one hand an immature crop, and, on the other, shattered fruit with excessive loss of oil. It has been found that the crop contains the highest proportion of usable seed and quality of oil when the fruit on the central and first order umbels turns a chestnut colour [11]. The dried seeds (fruit) and 2-4 mm diam., number 100-130 to the gram and possess a perfumed but slightly cloying odour. Russian and English coriander seed yield 0.8-1.2% and 0.3-0.8% oil on steam distillation. As in the case of juniper berries, coriander seed is selected for gin on the physical properties of the distilled oil and organoleptic quality in dilute alcoholic solution. The main component of the oil is d-linalool (60-70%); other oxygenated compounds, geraniol, l-borneol and n-decanal are present [4].  Monoterpenic hydrocarbons occur (10-20%), principally as γ-terpinene, d-limonen and ∝-pinene [12].

The dried root of Angelica officinalis (Hoffm) provides a third important gin botanical [4]. The plant is cultivated in the temperate climate of Europe and the distiller’s requirement is met with the produce of an entirely cottage industry in the East German provinces of Thuringa and Saxony. The roots are plaited and hung up to dry: during storage changes occur in the yield and properties of the oil which becomes darker in colour, higher in specific gravity and lower in optical rotation and acquires a musk-like odour due to the predominance of high boiling lactones.

I’ve definitely over looked Angelica, but he’s totally got me with musk-like and high boiling lactones. Does it conform to anyone else’s experiences? A nice thing about Simpson is that he dares use sensory descriptors.

Other ingredients in gin formulae vary with distillery practice and are generally included in lower proportions, often only a few ounces in a charge of several hundred pounds. Common minor ingredients are: sweet orange peel (Citrus sinensis L.); bitter orange peel (Citrus aurantium L.); lemon peel (Citrus limon L.); cinnamon bark (Cinnamomum zeylanicum Nees); cassia bark (Cinnamomum cassia Nees); cardamom seeds (Elettaria cardamomum Maton); nutmeg (Myristica fragrans Houtt); orris root (Iris pallida Lam); and liquorice root (Glycyrrhiza spp.).

A few ounces to several hundred pounds is a big claim. I know a lot of new producers are trying to push supporting botanicals forward in search of distinction and perhaps they shouldn’t. Some of these material are particularly high in oil contents and perhaps have unique thresholds of detection so the addition may be far more than symbolic.

Small quantities of these botanicals may have a considerable effect on the flavour of the gin, being rich in oils of highly odorous composition. Orange oil [3] is 90% d-limonene and cinnamon bark and cassia bark oils [4] contain 60-70% and 70-95% cinnamic aldehyde. Other gin botanicals have been reported; aniseed, caraway seed, fennel seed, calamus root, geranium leaves, grains of paradise, turpentine and cubeb berries [13,14].

Many of the botanical ingredients described lose important quantitative and qualitative fractions of their oil on storage. Juniper berries stored a year for gin suffer a reduction of 20% in oil content and between 15 and 30% in moisture [10]. Coriander seeds lose absolutely 0.18-1.5% oil on prolonged storage at -14°C and 30% total oil in a year when stored in large hermetically sealed containers [15]. Citrus oils undergo autocatalytic oxidation when the peel is exposed to light and moisture [3]. Decorticated cardamom seeds lose 30% oil in eight months [5]. Stored botanicals are liable to insect infestation. Careful storage of botanicals by the distiller is necessary if he is to produce a consistently flavoured gin or avoid the evaporation of his flavouring material into the atmosphere. Ideally the botanicals are stored under temperature and humidity controlled conditions.

The botanicals are proportioned according to formula and loaded into the still. A specified quantity of spirit, reduced to a strength of 80-100% proof is added (the exact strength depends on individual practice) and gin is collected as a definite fraction of the distillate. In Britain, gin distilleries and rectifying premises are not bonded but the still are secured by Excise lock and distillation of a set volumetric charge only is permitted. In North America, gin distilleries can be operated under bond.

The comment “the exact strength depends on individual practice” may conform to my idea that percentage alcohol in the still governs time under heat and that too low an alcohol content uses excessive time under heat (heating water you don’t need) while too high risks boiling the still dry.

The shape and design of the gin still and the manner of distillation constitute the third important factor in the manufacture of gin. The dimensions of the still relative to the volume and strength of the charge, the supply of steam to the jacket and cooling water to the head, determine the reflux ratio and hence the composition of the distillate. For a still of given reflux ratio and charge of specific composition the distiller modifies the production by selection of the middle cut of the distillate and also sometimes by a second distillation. Gin stills are built to exacting specifications by experts; and vary in capacity from a few hundred to several thousand gallons, measured to the level of the man-door in the pot of the still. The construction is always in copper and usually in the form of a simple pot still with tapering head which curves at the highest point into the downward sloping lyne arm (Fig. 1). The head may be expanded into a bulbous shape immediately above the pot. In some distilleries still heads are equipped with water jackets through which cold water is circulated during distillation; at another distillery a system of return flow conducts a preliminary condensate of higher boiling volatiles back to the pot of the still. All these features promote reflux in the course of distillation. The distillate is conveyed through a tubular condensor and is piped to inspection chambers for continuous measurement of alcoholic strength by means of in-line hydrometers; thence it passes to collection vessels. Stills are heated with steam generally applied to the jacketed base but some stills function with internal steam coils. Gauges for steam pressure, temperature of the liquid contents of the still, temperature of the distillate vapour and the condenser water are centralised in the modern distillery in a control panel.

The still head jacketed with water is sometimes called a “brandy ball” and is a method of providing optional degrees of reflux.

In operation the still is brought to boiling and the first few gallons of distillate rejected; this fraction is termed heads. Collection point for the middle cut of the distillate may be determined by an arbitrary quantity of heads, by the temperature in the column or by the appearance of the distillate. As the still charge is depleted of alcohol and steam pressure is raised to maintain distillation rate and when strength of the distillate falls to a predetermined value the still is struck and the distillate diverted into the second collection vessel. The still much now be exhausted of alcohol (tails) before the residue may be discharged. Combined heads and tails are called feints. The middle fraction of the distillate is gin, with a mean strength of 30-50 op. Still residues may be discharged to sewer after sedimentation and appropriate treatment. Feints are rectified in a special still with high reflux ration and the recovered spirit is added in constant proportion to the gin still charge. Feints may also be cleaned up by treatment with charcoal or potassium permanganate.

“by appearance” I think implies a demisting test where a sample is quickly taken and diluted to observe the degree of louching. This is correlated to how far has progressed and can probably be performed quickly enough to make a useful decision. The decision is gin product is of elevated importance because fractions are not recycled like other spirits. When the feints are recycled, they are stripped to neutral.

Alternative systems of distillation are sometimes adopted. In one variation the botanicals are place in a mesh tray above the liquid surface in the still. Volatile oils are extracted by heat and by contract with refluxing liquid but the botanicals so not undergo the maceration which occurs in the action of boiling. Some gin stills have been operated under reduced pressure.

What I haven’t figured out yet, is whether only the largest stills used gin baskets (my theory) because their time under heat was so long it compared to botanicals being boiled in a smaller still. Seagram’s early on was experimenting with partial vacuum.

In order to equalise the slight differences which result in the product of successive distillations in spite of the applications of rigorous quality control methods, gin should be blended in large holding tanks before transference to the bottling warehouse. Gin is diluted with distilled or demineralised water to bottling strength which in Britain is generally 70% proof. Water, free of dissolved solids, is used because otherwise the calcium and magnesium salts of hard ware are precipitated, giving sediments and chalky incrustations in the bottles [16]. Gin is colourless liquid and is often marketed in clear glass bottles. In order to attain the clarity demanded, gin is filtered (polished) before bottling, usually with cellulose-asbestos sheets in plate and frame or where throughput is large, with a filter-aid such as kieselguhr. Gin requires no period of laying down or maturation for improvement. The flavour derives entirely from the essential oils of the botanicals which are present in the condensate of the still. With gin the maxim might be ‘the earlier drunk the better’, for essential oils in dilute solutions tend to oxidise slowly with a detrimental effect on the flavour of the gin.

I think filtration and “polishing” are more important than some would think. I used to think polishing was only for dust and dirt but I think freshly distilled gin with always have errant out of solution terpenes that are some how emulsified and prevented from floating to the top. I’ve had big successes polishing very cloudy gins with sand (and there are lots of ins and outs of that), but the kieselguhr (diatomaceous earth) idea was new to me and I still do not exactly understand how it is applied. Stirred to attract particles then collected by the filter?

Analysis and quality control
The difference in flavour between well known brands of gin is distinctive even to the untutored palate. In order to maintain the distinction the distiller seeks to reproduce from one distillation to the next and from one year to another, a gin which is uniform in flavour. This is the aim of all producer of blended and compounded spirits but in the case of gin the process is more amenable to control. The whisky blender chooses from a wide range of finished whiskies, where as the gin distiller selects his raw materials and adapts his process to suit them. In the past, distillery organisation was based exclusively on the distiller’s palate and practical experience: today laboratory analysis and panel tasting play an important part.

I’m wondering if when Simpson says “where as the gin distiller selects his raw materials and adapts his process to suit them” he pretty much refers to scaling the botanical charge and blending stocks of botanicals to average out oil yields and their sensory properties. I suspect that the cut points stay as definite as possible batch to batch and the charges are reconfigured from different lots of botanicals to fit. And what of these master distiller’s? Do decisions at Tanqueray get made by the sole experience of a Tom Nichol or does he crunch numbers on the tasting panel, consult the analysis and paint by numbers? He did say recently that I make things too complicated. How far into the future are the international brands from the techniques laid out in this document?

The factors which determine the flavour in a bottle of gin have been described: spirit, botanical formula and technique of distillation. The distillation is a matter of control on the spot, with the still operator making adjustments in steam pressure and water flow from observations of the strength and rate of flow of the distillate. Modern distilleries utilise automatic steam valves, flow meters and other mechanical devices to obtain a precise control and the time of the entirely automated gin distillery approaches.

Did we ever get there? And if so, how small does it scale?

Botanicals and spirit were in the past selected wholly on the organoleptic evidence and while this method remains paramount in importance, it is necessarily supplemented by laboratory analysis. Control by tasting in the food industry has undergone a major rethinking in the last 10-15 years and the new methods are finding their way into traditionalist strongholds. In the US the standardisation of quality in distilleries through the use of taste panels numbering 20-30 persons is a widely employed technique [17]. Panelists are members of the distillery staff selected by test and they examine apparently similar samples daily in difference tests of the triangular or duo-trio type. Differences between the samples examined are expressed in statistical terms. Gin is amenable to this method of organoleptic examination because the accepted standard sample, properly stored, remains in good representative condition for a number of weeks. Panel tasting can be applied to finished gins as a test of uniformity, to spirit to check that it is up to standard and to dilute alcoholic solution of essential oils extracted from botanicals.

I was at a coffee roaster recently, Blue Bottle, and they were setting up panels for their quality control and every staff member knew how to quickly participate. I’ve tried to explain the importance to a few small distilleries and they just weren’t there yet.

Analysis of spirit has been restricted mainly to chemical methods: esters (expressed as ethyl acetate) by direct saponification; aldehydes (as acetaldehyde) using Schiff’s reagent; and fusel oil by the Komarowsky reaction. These methods give acceptable, meaningful results at intermediate and high levels of congenerics but approach the limit of accuracy when applied to the highly rectified spirits required for gin. It has been reported that the ‘fusel oil value’ of rectified spirits measured by the Komarowsky reaction is not necessarily an accurate measure of higher alcohol content but is a useful index of spirit quality [18]. Another widely used empirical measure of spirit quality is the permangranate time test which estimates the content of reducing substances by the rapidity with which a standard solution of potassium permangranite in contact with the spirit is decolorised. Ultra-violet spectrophotometry has been applied with some success to spirit analysis and provides a rapid instrumental assessment of inherent quality [19]. In Table 1 an analysis of an number of spirits used or proposed for use in gin distillation is presented together with a ranking of organoleptic quality by a small taste panel.

This all concerns the neutrality of the base spirit which is less of an issue now because it can be purchased from exacting specifications.

In the examination of gin botanicals for purchase or at intervals in storage, only juniper, coriander and angelica are likely to be subjected to a detailed laboratory analysis. The other botanicals would be distilled on pilot scale both individually and as ingredients in the formula and compared by taste against accepted standard. The essential oil of juniper berries, coriander seeds and angelica root are isolated from the plant material by steam distillation [20] and are measured volumetrically and for refractive index. The range of refractive index of the oil of juniper berries suitable for gin has been reported as 1.4840-1.4870 [10]. Lower values are indicative of a high content of low boiling terpenes which is undesirable in gin. Coriander and angelica oils should show refractive indices between 1.463-1.471 and 1.476-1.488 [4]. Ultra-violet absorption provides a rapid and valuable check of oil composition; juniper oil absorbs strongly in the region 220-240 mμ which is coincident in wavelength with a plateau in the absorption spectrum of terpinen-4-ol, and important constituent. Dilutions of juniper oil in 70° proof alcohol demonstrate an obedience of Beer’s Law at 225 mμ. Coriander oil begins to absorb at wavelengths less than 220 mμ but useful data are obtained if stray light factors are considered. Dilutions of the oil in alcohol are check by taste against standard samples. Moisture content of botanicals is determined by Dean and Starke tube.

New to me was that only the most significant botanicals were analyzed for oil yield and refractive index. I’ve slowly been doing a lot of work on the techniques and just found the block buster document on the subject from the horse’s mouth. Insignificant botanicals still get essayed but in an abbreviated form. I remember years ago tasting single botanical distillates from Citadelle, and each was startlingly beautiful with amazing focus and clarity of aroma. I thought that maybe they were prepared specially for the presentation, but they made have just been routine distillations performed for every batch of new botanicals.

Analysis of gin botanicals enables the distiller to base flavouring formula of his gin upon the definite properties of the batch in current use. Lots of berries or seeds with high and low oil contents may be blended together to give an appropriate intermediate level and a new season’s crop rich in oil can be phased into production with the least disturbance of the flavour characteristics of the gin. Purchase of botanicals each year from a range of samples supplied by the broker is made selectively on the basis of oil and moisture content, and composition and flavour of the oil in comparison with current stocks.

The finished gin is too dilute in oil to allow chemical analysis but control by tasting is supplemented by measurements of ultra-violet absorption. No published work exists on the application of gas chromatography to gin analysis but even with the most sensitive equipment, some preparation and extraction of sample is anticipated.

Other gins
Holland’s gin possesses a heavy, full-bodied flavour which derives not from the botanicals used in the gin distillation but from the original spirit; the gin character comes essentially from juniper berries but is overlaid with whisky-like congenerics. A mash containing up to 30% malt is fermented and distilled in a pot still with low rectification. The distillation may be repeated several times but the final spirit (moutwijn) does not show the neutral characteristics demanded for London dry gin. Originally the botanicals were added to the fermented mash before distillation.

Steinhager (Germany and Austria) or Borovicka (Hungary) is the distilled product of crushed fermented juniper berries [21]. It is twice distilled to a final alcohol strength of 70-85% proof. The stillage is and important source of oil of juniper.

Old Tom is a gin sweetened after distillation of approximately 3% w/v sugar. It is uncommon now in the English market but is still exported. Sloe gins, lemon and orange flavoured gins are made by steeping finished gin in the fruit or peel.

Thanks are due to the directors of W.&A. Gilbey Ltd for permission to publish this article; to Mr. M.S. Aldridge, distiller for his co-operation and Messrs M.G. Farey and C.C.H. Macpherson for analytical work.

1. Encyclopedia Britannica, 1964
2. Customs and Excise Act, 1952, Section 172(5).
3. Guenther, E. ‘The Essential Oils’, Vol. III (1949), D. Van Nostrand Inc. New York.
4. ——, Ibid., Vol. IV (1950), D. Van Nostrand Inc. New York.
5. ——, Ibid., Vol. V (1952), D. Van Nostrand Inc. New York.
6. ——, Ibid., Vol. VI (1952), D. Van Nostrand Inc. New York.
7. Motl, O., et al. Chem. Listy (1956), 50, 1282.
8. Hirose, Y., et al., Nippon Kagaku Zasshi (Japan) (1960), 81, 1776.
9. Klein, E. and Farrow, H. Dracogo Rept. (1964) 11, (10), 223.
10. Willkie, A.F et al. Ind. Eng. Chem. (1937), 29, 78.
11. Chikalov, P.M. Maslob-Zhir. Prom. (1962), 28 (2), 26.
12. Ibeda, R.M., et al., J. Food Sci. (1962), 27, 455.
13. Levin, H.J., Am Wine Liquor J. (1940), 7, 26, 33.
14. Jacobs, M.B., Am Essent. Oil Rev. (1949), 53, 54.
15. Rabora, N.V., Spiritovaya Prom. (1961), 27 (5), 13.
16. Warwicker, L.A., J. Sci. Food Agric. (1963), 14, 371.
17. Brandt, D.S., Lab. Pract. (1964), 12, 717.
18. Berganger, E., and Babel, W., Nahrung (1964), 8, 192.
19. Merke, R., et al., Branntweinwirtschaft (1960), 100, 479.
20. Clevenger, J.F., J. Amer. Pharm Assoc. (1928) 17, 345.
21. Stucklik, V., Sbornik Ceskoslov. Akad. Zeinedelske (1950), 22, 363.

Process Biochemistry, October 1966

Rare Vantage: Beverage History From The Spirits Chemist

I recently acquired another forgotten gin document, titled The History of Gin, by the chemist, D.W. Clutton, who gave us some of the most important works on gin distillation and chemical analysis. But what would such an important chemist speaking in 1972 have us know about gin? Read it and find out.

Clutton also wrote a wonderful history of rum that is notable and well organized. There are brilliant snippets and descriptions plus a bibliography of forgotten articles not seen elsewhere (that of course I’m already tracking down).

I also just digitized my copy of Herman Willkie’s Beverage Spirits in America —A Brief History (I apologize, but you will have to rotate the view of the PDF once you open it). This was an adaptation of Willkie’s 1947 address to the Newcomb society. It also answers the question: what would the greatest distiller of the 20th century have us know about American beverage history? And he goes on to say a great deal of things that were new to me. Some parts are so wonderful I dare not spoil them for you.

Clutton’s history of gin is really interesting and I’ll highlight what caught my eye. The most interesting parts are centered around Plymouth Gin and Old Tom.

J.B. Priestly described Plymouth gin as the gin ‘with a suggestion of a fresh morning at sea about it’.

The production of Plymouth gin is very localized. Messrs. Coates & Co. (Plymouth) Ltd. are the sole agents for its manufacture (with the exception of New Zealand, Germany, and Italy, where it is produced under license).

This was new to me and surprising as lately they hype their appellation status. More spirits are licensed for production in multiple locations than you’d think.

The secret of the success of Plymouth gin derives from the soft pure water which runs from the river Meavy, through the granite of Dartmoor. Spirit is obtained from grain whisky distilleries in Strathclyde, or occasionally from a London grain spirit supplier.

I began to wonder why he goes into such detail. Either Clutton was an employee or they just hosted him. It seems like Plymouth existed in a world where gin was simply a commodity but as often as possible they tried to elevate it to something fine.

During the war, molasses spirit had to be used, much to the disgust of the manufacturers. Eventually, however, the switch was made back to grain spirit, and this was commemorated by the following telegram sent from Glasgow—

From the land of Scotch and Bonnie Lasses,
We’re glad you’ve given up molasses
and Plymouth gin is once again,
The very best and made from grain.

The grain spirit is pumped into the still and reduced with the famous water to ca. 25° over proof and the spirit is rectified. The spirit is then pumped into a pot still and the botanicals are added. The centre portion of the distillation is reduced in strength, taken into bond and bottled as Plymouth gin. ‘Plym-Gin’, as it is affectionately called, is exported to 80 overseas markets.

The term ‘dry’, as applied to London dry gin, means that the over-all flavour content is low. This arises since the gin is distilled from extremely pure spirit and a low proportion of botanical ingredients.

I interpret “low” here as low enough to be crystal clear. If the gin is cloudy from insoluble terpenes, it either has too much flavour and/or is cut improperly. I’ve been exploring a new technique for post distillation clarification of cloudy gins and I’ve having spectacular success. It will be the defacto practice once I write it up.

Another explanation [of Old Tom gin’s origin] of the term was given by Boord’s (Distillers) Ltd. of London (Est. 1726) They established that Old Tom referred to Old Thomas Chamberlain of Hodges Distillery. He was an experimenter in gin flavourings, and once added sugar syrup to London gin. One of Boord’s ancient labels showed a picture of ‘Old Tom’ Chamberlain.

Old Tom is a gin sweetened, after distillation, to 3 to 6% w/v of sugar (or occasionally glycerine). Occasionally the sugar syrup is flavoured with orange flower water, and is known as capillaire. Old Tom is no longer popular in England, but is still exported.

This wonderful Difford’s Guide article gives even more background to the origins of Old Tom. I think its references mainly comes from a book titled Slang and its Analogs.

Clutton’s Rum had some spectacular passages I’ve love to quote, but I’m short on time.