The Flavour Components of Whiskey in Three Acts

Flavour Components of Whiskey. I. Distribution and Recovery of Compounds by Fractional Vacuum Distillation

Flavour Components of Whiskey. II. Aging Changes in the High-Volatility Fraction

Flavour Components of Whiskey. III. Aging Changes in the Low-Volatility Fraction

This novel experiment explores how different components of a whiskey change over time in a barrel. The novel part is how they track the components which relates to experiments I have done with the past and my own fake aging technique.

The first part of the paper details how a whiskey can be separated into different segments via fractional vacuum distillation. What they perform is quite complex to execute and certainly beyond me, but actually possible with off the shelf components as they prove. They cut a whiskey into five distinct fractions while in my own greatly simplified experiments, I cut whiskeys only in half.

What is cool about this set of papers is that it validates my intuition that the bottom half, the least volatile fraction, represents a significant portion of what barrel aging contributes. I had taken this aqueous fraction in the past and added it to other high proof spirits to synthesize aging which can be just plain fun to explore or possibly a predictive tool for a distiller. I had also cut spirits in half down the lines of volatility, manipulated the fractions independently then rejoined the two fractions which this paper somewhat validates as representative with their own organoleptic experimentation though they did control for far more variables than I did.

The second paper, which looks at the most volatile fraction is a good read which I don’t have the time to completely detail. The most notable part of it for me, which I need to learn significantly more about, is this tidbit:

In the case of wine, acetates are considered more important than ethyl esters of fatty acids for intensity and quality of aroma (van der Merwe & van Wyk, 1981). The same is likely for whiskey because of the low sensory odour threshold values of these compounds (Salo, 1970).

I can’t speak in any real depth about acetates, but I think they form through more complicated aging reactions rather than relatively easier to understand processes like acid catalyzed esterification of ethyl esters in the still.

Part three is particularly cool because to some degree you can play along easily since they are concerned with aroma compounds in the aqueous solution. They isolate their aqueous solution with a complicated fractional vacuum distillation procedure but ball park approximations can be gotten by simply putting a whiskey in a food dehydrator until the alcohol is removed.

The paper starts to get really complex and starts offering new ideas for authenticating spirits based on ratios of congeners. Page 5 of part III has some major errors in the scanning that removes part of the page but its in a section that is very technical. Eventually they isolate a few congeners (phenolic esters) they believe are crucial to mature character and then syntheticaly add them to younger spirits to organoleptically test with a tasting panel whether they increase the perception of maturity. The relationship of their contribution is not straight forward but eventually, at high concentrations, they do increase the perception of maturity.

One of the big take aways here is how we might design educational tasting experiences for spirit tasting rooms and educational seminars. These papers validate my idea that spirits can be cut into pieces along the lines of volatility and then reconstituted in various ways. The fractions can also participate in mash-ups and when abstracted in different ways, teach us new things about perceptual thresholds which I’ve only explored in the past at the lowest level.

Also, check out the bibliographies. This team references older material I’ve never seen, possibly because they own unique collections. One of their books is a rare gem I’m now trying to acquire, bet you can’t spot it!

Standardizing Botanicals: Me and My Soxhlet Extractor

[This is just one post in hopefully a series about learning to standardize botanical charges for distillations most particularly gin, also aromatized wines, and bitters.]

Long ago I linked to a great paper called Controlling Gin Flavor from Herman Wilkie’s team at Hiram Walker in 1937. Wilkie is a very important distilling figure and it should be known is the true father of vacuum distilled alcoholic beverages. In the paper, back in 1937, Wilkie mentions a new era they had just entered where the botanical charge of a gin was scaled for oil yield. This acknowledges that the oil yield is inconsistent and if you just weigh your botanicals, you will end up with a less than consistent product. And sadly I suspect we have returned to the pre-Wilkie era which in my opinion is less than craft.

Gin production in the past has been characterized by lack of control over many of the important variables such as quality of spirits, quantity and quality of flavor in the various botanicals used, variable types and methods of operating the still, etc. Critical study of these variables disclosed valuable information which led to standardization of spirits and operations which, with proper selection of botanicals and regulation of the quantity of each ingredient used in the formula in accordance with its flavor value, now permits the production of gin under technical control which guarantees uniformity and quality of final product.

- Controlling Gin Flavor

Wilkie notes that some distillery labs use the Clevenger Method of finding the oil yield which simply employs steam distillation while Hiram Walker uses a method, likely a Soxhlet extractor, with an ether as the solvent. The oil extracted is simply weighed then converted to a percent oil yield. What the paper doesn’t mention is how large their sample size is which is very important for what I aim to do.

No small producers to my knowledge are performing any of this analysis and these days it should be easier than ever with teaching resources like youtube, equipment procurement resources like ebay, and already purified chemicals affordably available from the likes of Fisher Scientific (but you need a commercial account and clearance to ship).

photo 5

To explore this type of analysis I bought a 500 mL Soxhlet extractor from ebay and already made some miss steps. Many Soxhlet extractors use a thimble to hold the botanicals and I bought one for $40 that I probably didn’t need. According to some youtube soxhlet demos, the bottom of the extractor can be lined with a simple bleached cotton pad and the botanicals simply tucked into a coffee filter. Its a much cheaper solution and even increases the volume the extractor can hold.

photo 2photo 1
The soxhlet extractor works by condensed solvent filling a chamber holding the botanicals until it reaches the level of a siphon tube eventually drains the chamber similar to flushing a toil. the drained solvent eventually evaporates refilling the chamber with fresh warm solvent. This means that the duration for running the apparatus can be considered in terms of flushes. Great advice is taken from here.

The amount of powder depends on the weight of the drug. If the powder is from roots or stem parts, it will be comparatively heavier than leaf powder. So heavier powder will be needed more as it will settle well in the extractor. What I mean to say is that the weight of the material is not a problem. It depends upon the size of the extractor you are using. Only thing is that it should be filled in extractor at least 1 inch below the siphon tube to avoid its entry there and finally in the flask.

 

So do not over fill the cavity.

Solvent should be filled from the top and not directly in the flask. Once you start filling the solvent you can see the drug getting wet and finally you will add it till the first cycle runs. Now you should add solvent which is sufficient to run at least two to three more cycles (from the top only to get initial efficient extraction). This way you will find that the drug is entrapping solvent for one cycle and flask is having sufficient solvent to run two to three more cycles. This is the normal practice. Regarding time for extraction, it is normally 24 hours or 72 cycles. But you can check for the completion of extraction when you see that the solvent coming through the siphon into the flask has become free of extracted material. For that you can use a watchglass. Just when the cycle is about to run, you need to take little (1-2ml ) of the solvent from the cycle in a watchglass and allow it to evaporate at room temperature. If you find a deposition in the watchglass, then it needs further extraction and vice versa.
Hope it will help you.

 

72 cycles (or flushes) seem like a long time but you can also refine your process by observing when the solvent starts to run clear. I think the 1-2 mL sample can be thiefed out of the extractor by reaching a pippette down through the condensor which is open (though you can’t really see it in my picks) then evaporating it. A microscope might aid in observing the residue. Once the amount of cycles are standardized, the time per cycle can be calculated and the total time taken from that.

As far as I am concerned, we use 10gm of power of plant materials for each 100 ml of solvent. For example, the solvent container that you used has a 500ml capacity means, we can pour 300ml and process 30gm of plant power (10gm per 100ml of solvent). In our lab, we will continue the extraction process up to the point, where the solvent color in the thimble becomes colorless as water.

 

So here is a best bet.

If we come to the point of solvent type, there is a custom to use three types of solvent, i.e. high polar, mid-polar and non-polar solvents. Some researcher uses any one solvent for each of the categories, however most of others, can decide a particular solvent, especially either from non-polar (such as hexane) or high polar (methanol, ethanol).

This something I haven’t completely figured out. I used hexane because its what I had. It is also less toxic than dichloromethane and waste disposal does become a consideration. In the end I lost about 50 grams of hexane (33.2 mL) which were stuck to the botanicals when I removed them from the extraction chamber.

photo 10photo 6These measurements with the scale are about 20 minutes apart.

I then tried to recover the hexane from the flat bottomed boiling flask.

photo 1

 

This is actually an early photo after probably one flush. Most often the low boiling point solvent is recovered with a rotovap which is known for speed and efficiency but I only had a high school quality vacuum distilling rig.

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Yet it was able to collect the hexane.

photo 8

 

Some how I only recovered 150 mL of my initial 300 mL of hexane, but I do know 33.2 mL was stuck to the botanicals and was lost to the atmosphere. Better systems could likely dramatically decrease the loss and inefficiency. Glycol instead of water to condense both rigs might be a good place to start.

photo 7

But what did I get? Pretty much nothing. My first test was run with wormwood which was likely a bad idea because the typical oil yield is so low (0.35%) where if experimenting with cloves they might have yielded over 10% and given a better feel for the process.

And what exactly is all that stuff and can it be thought of as oil? Should the contents of the flask have been filtered before it was vacuum distilled? We think of oil as volatile, so when we examine botanicals with very low oil yields but very high amounts of soluble non-volatile stuff like bitter alkaloids (not sure if I picked those up actually), should a different method be used like steam distillation?

It looks like somethings precipitated but are they still figured in the oil weight?

I also suspect a big problem I’m having is that I’m using old and tired botanicals who’s oil yields are not anywhere they should be and thus have no place in a gin. So I think I’m experimenting with some failures but there should be some value in there somewhere.

The next step is to try out my new glass steam distillation rig with clevenger oil separator. More to come.

 

The stepping stones of analysis and a cry for help (· · · – – – · · ·)

I’ve slowly read every major book on distillation and probably 150 journal articles in the last few years. The punch line is that just like fine wine was made possible by the laboratory (just like the kings of Napa, Mike Grgich and Warren Winierski, would tell you), craft spirits will also be a product of the lab, and not many new distilleries are running labs. This unfortunately means that only the big guys are craft but that doesn’t have to be the case.

My idea has been to slowly explore spirits analysis in little steps and build a valuable skill set as well as share everything to elevate the new distillery movement. One thing I’m seeing is that for many small distilleries to stay open in saturated markets, they will have to rely on their tasting rooms for revenue. In a tasting room, it will soon be apparent that a portfolio of three products probably won’t cut it. Tasting rooms will need elaborate cocktail programs and legally will have to fabricate small batches of products like orange liqueurs to show off the core products. This orange liqueur among many others will never be sold out the back door (saturated market) but rather just be used in house and possibly be sold out the front door because many tasting rooms can operate like liquor stores.

So, for an orange liqueur to be made in small batches, some competitor analysis has to be performed on the likes of cointreau and grand marnier such as sugar content, alcohol content (before sugaring), and the weight of the aroma. The liqueur will then be assembled in a robust, paint by numbers process where a great product is made without tons of man hours or tying up people for tasting panels. Years ago I figured out elegant ways to measure alcohol and sugar content (via hydrometry without sacrificing a sample) but what about the weight of the aroma? and how the hell do you standardize your charge of peels when the oil content varies so much? That is the skill set we need to be returned to common knowledge!

So far, the answer to finding the weight of orange aroma in an orange liqueur is liquid-liquid extraction using intense, hazardous, organic solvents like iso-octane, hexane, and dichloromethane. The exotic solvents require a fisher scientific account and clearance to ship them so not everyone can play with this stuff. They also require lots of reading and safety training to handle properly (though it is nothing too extreme). The same solvents can be used again for measuring oil yield of botanicals using a piece of glassware called a soxhlet extractor which is a priceless skill for a distillery lab.

I’ve been exploring this and spending considerable money in the hopes that it will launch a lot of ships. What I don’t know and need help with is the full potential of liquid-liquid extraction. You see it in a lot of spirits research papers because it is used for sample preparation for GC-MS and it is described in a lot of the modern advanced texts but not in any specific detail or with vouched for Modernist Cuisine style best bets which is what we all need.

First a tiny overview of liquid-liquid extraction. Powerful orangic solvents with very low boiling points that are immiscible in ethanol* and water* are mixed with a spirit. The organic solvents will mix just like oil and water but their solvent power will pull congeners out of the ethanol and water. Eventually the organic solvents can be separated with a separatory funnel. Their boiling points are so drastically different from the congeners dissolved in them that vacuum distillation (solvent recovery) or sometimes just putting a fan on them (expensive sacrifice!) is enough to separate and isolate the congeners. The asterisk is for organic solvents that form an azeotrope and suck up tiny amounts of water or ethanol, but simple methods can be used to “dry” them.

What I just described is the batch process and its pretty easy but has some limitations. So far little globules of emulsion (which I need to identify but are probably aromatic oils) cling to the sides of the glass and need to be rinsed out with more solvent (expensive!). Smaller size glassware tailored for the batch might minimize this cling via reducing the surface area available to cling. Some descriptions of the batch process (not in a spirits context) use multiple iterations to extract as much as possible which is not a big deal if you can recover your solvents in a vacuum still.

Most spirits chemists isolate congeners to prepare samples for GC/MS analysis. Once the solvent is evaporated they don’t need to perfectly remove every bit from the glass and can work with batch sizes as small as 30 mL. My idea is that if the batch size is scaled up dramatically to a liter, what is extracted from say an orange liqueur can be weighed with a jewelers scale that does 1/100 of a gram. Just knowing the weight of the dissolved orange essence will get you squarely in the ball park. The problem is that no researchers use my scaled up 3rd world method because they have PhD’s, big budgets, and are in the GC/MS era. What I have going for my hunch is that I am the guy that figured out you can even measure carbonation with a kitchen scale!

Long ago I read a paper from the 1970′s where scientists were pioneering liquid-liquid extraction sample preparation for the study of gin. They were using Freon-11 (which is now banned for its effects on the ozone). These guys were concerned that their sample was representative of the gin so once they extracted all the gin congeners, they re-dissolved them in vodka and drank it! and then compared it to the original gin! If you have a reliable vacuum still, what you extract from the point of view of a chemist is drinkable! (but I’d use extreme caution, though most of the solvents smell like rubber cement which makes incomplete separations easier to spot).

A problem I’ve been having is I don’t think my samples are representative. I’m leaving way too much aroma behind in my gin test material. I took my organic solvent blend from a recent study on a gin (which might be a red herring to support a patent that should be bogus) and I think the process might call into question their results. Or I’m just new at this and am missing something. I’m using a 1:1 blend of Hexane and Dichloromethane and using the batch process with just one iteration like in the study, yet a significant amount of juniper aroma lingers in the ethanol-water of the gin.

Another options is to use a continuous liquid-liquid extractor and some are described in modern spirits texts but not with any real guidelines, best bets, or testimonials. I’d love to try one but the glassware starts to hit $500 to $1000 dollars very quickly (with no testimonial they work in this context!). Continuous extractors run small amounts of solvent through the spirit in a loop where at one point in the loop the extracted congeners are separated from the solvent by evaporation and the clean solvent is run back through the loop. These rigs take up not insignificant counter space and run sometimes for sixteen hours. I’m not afraid to pay for one but finding counter space and sixteen hours is a big challenge. But keep in mind this analysis only has to be performed once and then can be shared by the distilling community!

Once we know there is X mg of dissolved orange oil in each liter of quality, intuitive-to-use orange liqueur, we can elaborate the process we learned slightly. We can use the next extraction tool which is the soxhlet extractor. We place 100 grams or so of orange peel into our extractor and start to draw the essential oil out of it. This type of extractor also runs in a continuous loop for numerous hours unattended and there are lots of Youtube videos that show them in action. Once the solvent is separated by vacuum distillation we will know how much oil is in every 100 grams of peels which will change often dramatically with each batch of peels. If we just weigh the peels and throw them in the still, the oil yield will be wacky and the product will be inconsistent, but if we scale the botanical charge for oil yield, we will have a much better standard and it will open a lot of doors to taking on new botanical sources while hitting a higher standard of product consistency.

Two more important things. A steam distillation rig, designed to produce essential oils, can also ball park the oil yield but it is an inferior method (but we are concerned with affordable stepping stones! so do explore, especially if you have no access to exotic solvents!). The most important thing is that this procedure of measuring oil yield can scale up to all the botanicals that come through the distillery. The full botanical charge of everything from gin to absinthe to amaro to bitters can be standardized for increased product consistency and this is the skill set. What we need are best bets, testimonials, and what-ifs answers, and Youtube videos. Many distillers working with botanicals are not standardizing their charges because of a false sense of consistency. Yes, supply chain management for botanicals is staggeringly more advanced than it was decades ago, but if you want to get off the beaten path, and forage, or grow your own, or seek terroir, you need at least this very basic laboratory analysis.

The plywood whiskey barrels that inspired the Eames recliner

Not many people know this, but this chair (which I own a reproduction of) was directly inspired by plywood whiskey barrels. (I qualify this assertion because it looks like its made from cut cross sections of plywood whiskey barrels)

I finally tracked down the IRS internal communication on aging whiskey for four years in plywood barrels [PDF] from 1950. There is still an eight year update that I haven’t been able to locate but I’m working on that. The four year paper was very tricky to find. It had a WorldCat entry unlike many of the other IRS internal communications, but it generated an error that could not locate the library that held the record. The trick was to contact WorldCat via their tool for correcting database errors. (I might have pretended to be my local library) and I asked them: if no library is listed as the record holder then who created the record in the first place?

I assumed the creator of the record would be the record holder. This information is not publicly displayed and WorldCat revealed the library to be the Forest Products Research Laboratory library which is a U.S. government organization. The library claimed they could not help non-employees but they were able to be sweet talked (saying #whiskey gets you really far these days!). Besides digitizing the paper, these wonderful people even went through the card catalog and gave me some great related citations to pursue down the road. It turns out a nice amount of work has been done on barrels made from veneers.

I have mentioned the plywood whiskey paper before and included drawings from a 1944 patent application to help people visualize the process of making the barrels (I have been assembling a team to produce some of the barrels!)

The paper is interesting and its scope is far more extensive than I would have guessed. The barrels of three different manufacturers were distributed among 13 participating distilleries for a total of 40 different plywood aged whiskeys. Two manufacturers used only oak while one manufacturer used a combination of oak and maple.

The results of the study are fairly easy to follow, but are not necessarily encouraging for the use of plywood barrels to create products resembling Bourbon which traditionally relies on the highest quality first use barrels. The manufacturer using maple produced significantly inferior results to the other two which used only oak and the 100% oak plywood barrels still produced much lighter and thus inferior results compared to staves. The problem might be the sourcing within the tree for the oak. If the veneers have to be the same quality as a stave, then why not just stick to staves?

The results do not nullify the use of plywood barrels. They just can’t be intended for first use scenarios like Bourbon but rather might be suitable for rum or gins perhaps with interesting aromatic veneers such as cedar. One issue the paper mentions is the adhesives used to affix the veneers. Leaching into the spirit was not a problem, but rather the issue was creating too much of an impermeable layer for the barrel to breath through sort of like how some barrels are lined with paraffin wax first (often grappa). Adhesion could probably be reconsidered with modern inert options and the possibility of creating channels of permeability so barrel breathing can be maximized.

If you want to get in on our test run of plywood barrels, please shoot me an email with your intended use, your concerns, your ideas, or anything relevant that is on your mind.

“Muck Hole” Not “Dunder Pit”

The previous post contains an account of making Jamaican rum from a 1911 text on Cane Sugar from a renowned sugar technologist at the experiment station of the Hawaiian sugar planters association. The account very briefly explains the various cisterns used for preparing all parts of the sugar wash and uses the (new to me) term “muck hole” as opposed to the term “dunder pit” which many rum talkers like to throw around. True Jamaican rums had dunder added, which just implied stillage, but they also had a quotient added called flavour, which is the legendary refermented portion. Not all of Jamaica made heavy, flavoured or German rums, they also made clean rums. Many people today are confused on what style of rum is represented by Wray & Nephews OP or Trelawny OP. They are unique relative to other clear rums but probably do not see any of the flavouring technique.

“If common clean rum is being made, stick to common clean and never allow things to drift in the directions of making flavoured rum in the pious hopes that you may wake up some day to find that you have become famous by making flavoured rum where it was never made before. You are much more likely to find an enfuriated Busha awaiting to tell you that your services are no longer required on that estate.”

Searching google books for “muck hole” many great explanations of Jamaican rum production come up as well as one particular old text that is basically the holy grail tell-all of Jamaican rum making at the beginning of the 20th century. I do not not believe this text is known to popular culinary or even the new distilling scene.

Report on the experimental work of the sugar experiment station (1905)

The text is pretty amazing and has staggering amounts of data on experiments conducted. The PDF was scanned poorly and is not searchable, but the content is so historically significant I might be tempted to re-type parts of it over so they are easier to use. Previously, I did not believe there were any works this scholarly being done at this time period concerning rum. It almost seems more advanced than works concerning whiskey or brandy and isn’t listed in any bibliographies that I know of. There is even an appendix of “Lectures on fermentation in relation to Jamaica rum as delivered at the Course for Distillers at the government laboratory in 1906 by Charles Allan, B.Sc.” (PDF p. 284). A likely reason for the advanced nature of the content relative to works of the same time by Scottish researcher S.H. Hastie is that Allan had carte blanche access to whatever he wanted with no legal restrictions unlike Hastie who was severely constrained by the rules of the excise officers.

The text is a compendium of three sections written over three years and at the end of each section rum production is discussed and the author’s handle on the subject gets better and better until finally he pretty much unlocks the secrets of muck hole bacterial fermentations.

Solids from the dunder go into the muck hole. These solids which are pretty much completely composed of high acid spent lees undergo a particular bacterial fermentation which produces increased amounts of fatty acids, notably butyric. The muck hole is essentially a pH sensitive bio reactor that is started and stopped constantly by the addition of alkaline lime marl. Besides stalling out with too low a pH, if the muck hole was neglected, the prized fatty acids would continue to break down into simpler molecules like ammonia, but when lime is added and the pH rises, fatty acids are also locked up as salts. Muck can be drawn off or more dunder solids added and the process restarted. Many rum talkers claim the content of the pits could be decades old but I suspect the break down of chemical compounds into undesirable forms like ammonia would not permit this and the contents rather were/are at most only from the previous seasons production.

A wash for a Jamaican rum is composed of sugar cane skimmings, dunder, acid, molasses, and flavour. Deconstructing all these terms is tricky and here is my best shot. Sugar cane skimmings could imply fresh sugar can juice, which was known to be added to Jamaican rums. Dunder here is nothing re-fermented but rather just stillage from a previous distillation similar to backset used in the sour mash process. Acid, believe it or not, implies sugar cane vinegar and its role is a clever chemistry trick I’ll discuss next. Molasses is the molasses you’d expect, and flavour, finally, is the muck.

The muck is full of lime marl / fatty acid salts which are essentially locked up in a non-volatile form and need the acid, again also said as sugar cane vinegar, to unlock. I learned about this concept intimately when creating the Tabasco aromatized gin recipe for my Distiller’s Workbook. The acetic acid in the Tabasco needs to be locked up as a non-volatile salt using baking soda so it does not carry over into the distillate. The chemistry concepts are also masterfully explained in Peter Atkins book Reactions. In the Jamaican rum context, the addition of acetic acid to the muck changes the bonds between the lime marl and a portion of the other fatty acids releasing them to participate in future reactions such as acid catalyzed esterification. So the most common shortest chain fatty acid, acetic, trades places with the longer more noble fatty acids created in muck hole and become linked up as salts with the lime marl.

The author gives the proportions of sample mashes but doesn’t explain how they are assembled. The muck and sugar cane vinegar could be thrown in with all the other components or left to react independently and then the newly formed lime marl / acetic acids salts separated and the more noble mixture added to the skimmings, molasses, and dunder. The latter option makes the most sense from a chemical perspective.

“Distillery work”, PDF page 471 is also worth a look.

Using google books, five more references were easily findable describing the muck hole and the use of lime. For some reason none of the PDFs are searchable nor can text be copied and pasted from them. The two 1913 sources and the 1920 seem mostly plagiarized from each other.

The Chemical Age Volume XVIII July-December 1913

The School of mines quarterly A journal of applied science vol. XXXIV 1913

Food Products by Henry Clapp Sherman 1920

British and Foreign Spirits by Charles Tovey 1864

West Indian Bulletin Great Britain Imperial Dept. of Agriculture for the West Indies Vol. VI 1906 (this book looks especially cool!) The manufacture of Jamaican rum is discussed on PDF page 584 and is a summary of Charles Allan’s work in Jamaica which is quite good and fills in some pieces missing in the text from the experiment station. It gets interesting when he starts to paint a broader portrait and gives his opinions of the industry.

Once these imperialist chemists unlocked the secrets of the process, they also uncovered serious inefficiencies. Large amounts of sugar go wasted in each step and some processes were left to run away creating wastes. Spirits production was still very competitive back then and the authors discuss whether it was worth it to cut yields to make a higher ester product at the hopes of making a higher profit. It seems like changing distillery practices incurred more risk and often was just a break even proposition. Advances slowly move forward over the years probably until we get to Raphael Arroyo’s work on heavy rums patented in 1945 where the techniques used today pretty much get settled.

To quote Arroyo:

It has now been found that heavy rums of excellent type and with high yields and fermentation efficiencies can be obtained by a procedure comprising:
1. The subjection of the raw material to a pre-treating operation which fits it for its intended use.
2. The selection of yeast and bacterial cultures adapted for symbiotic fermentation of heavy rum mashes.
3. The employment of optimum conditions for the production of alcohol and symbiotic fermentation for the production of aroma and flavor, wherewith to obtain high yields and fermentation efficiencies with a rapid fermentation, and a high quality of final product.
4. The employment of a proper distillation method for the resulting beers.

In the Arroyo technique, no dunder or muck hole is used but rather controlled inoculation of selected bacteria in the main ferment coupled with other tightly controlled fermentation variables. Looking at the balance between tradition and innovation it wouldn’t be surprising if for the sake of tradition Jamaica used a modified version of the arroyo method where the bacterial fermentation was relegated to some sort tightly controlled cistern / muck hole / dunder pit. One interesting thing to note in Arroyo’s technique is the way he uses alkaline lime during production.

“The addition of the milk of lime during the initial stage of the pre-treatment process has three main purposes:

1. It prepares the medium for the development during fermentation of the most important ingredient in the aroma of heavy rums, being the essential oil or mixture of essential oils known as “rum oil.”

2. It neutralizes the free fatty acids which are always present in molasses, thus eliminating the danger of their volatization during the heating operation which immediately follows, but permitting the reliberation of these fatty acids from their calcium salts upon the sulphuric acid addition to the already cooled thick mash in the second stage of the pretreatment, so that they are then available for the formation of valueable esters later during the fermentation period and under the catalytic action of the esterase produced by the yeast.

3. The disturbance produced in the medium through the alteration of pH value occasioned by the milk of lime causes a copious precipitation of organic bases, molasses gums, and mineral ash constituents of the molasses, and this precipitation is enhanced by the action of the heat applied.

The works of the sugar cane experiment station have been of immense value and it wouldn’t be surprising if other similar works exist for the other islands, particularly those colonized by the English. Maybe there is a text out there that explains the significance and ins & outs of wooden boilers as opposed to copper.

A completing scanning of Raphael Arroyo’s rare text Studies of Rum (spanish) can be found here.

More from the Journal of the Society of the Chemical Industry, volume 26, 1907 which features a very interesting comment section.

The first  named needs no special description. “Skimmings” consist of the scum which rises during the boiling of the cane juice. Before they are allowed to undergo acid fermentation, either alone or in presence of the crushed canes (or “trash”). “Dunder” is the spent wash from the stills.

Early Accounts of Arrack Et Al.

CANE SUGAR (1911 PDF):

A TEXT-BOOK ON THE AGRICULTURE OF THE SUGAR CANE THE MANUFACTURE OF CANE SUGAR, AND THE ANALYSIS OP SUGAR HOUSE PRODUCTS; TOGETHER WITH A CHAPTER ON THE FERMENTATION OF MOLASSES NOEL DEERR, SUGAR TECHNOLOGIST AT THE EXPERIMENT STATION OF THE HAWAIIAN SUGAR PLANTERS’ ASSOCIATION ; AUTHOR OP ” SUGAR AND THE SUGAR CANE.”

Here are two choice excerpts on rum making. Production processes for a few other regions are described but they aren’t so unique. The author continues the chapter will more excellent information on rum production and still operation of historical significance.

p. 562

Java.24—In Java and the East generally, a very different procedure is followed. In the first place a material known as Java or Chinese yeast is prepared from native formula. In Java, pieces of sugar cane are crushed along with certain aromatic herbs, amongst which galanga and garlic are always present, and the resulting extract made into a paste with rice meal; the paste is formed into strips, allowed to dry in the sun, and then macerated with water and lemon juice; the pulpy mass obtained after standing for three days is separated from the water and made into small balls, rolled in rice straw and allowed to dry; these balls are known as Raggi or Java yeast. In the next step rice is boiled and spread out in a layer on plantain leaves and sprinkled over with Raggi, then packed in earthenware pots and left to stand for two days, at the end of which period the rice is converted into a semi-liquid mass; this material is termed Tapej and is used to excite fermentation in molasses wash. The wash is set up at a density of 25° Balling and afterwards the process is as usual. In this proceeding the starch in the rice is converted by means of certain micro-organisms, Chlamydomucor oryzae, into sugar and then forms a suitable habitat for the reproduction of yeasts, which are probably present in the Raggi, but may find their way into the Tapej from other sources. About 100 lbs. of rice are used to pitch 1000 gallons of wash.

24. From Lafar’s Technical Mycology, Vol. V.

p. 563

Jamaica.—Allan25 gives the following outline of the process followed in making flavoured spirit:—”The wash is set up from skimmings, dunder, molasses, acid and flavour. Acid is made by fermenting rum cane juice which has been warmed in the coppers. To this juice is added dunder and perhaps a little skimmings. “When fermentation is about over, the fermenting liquor is pumped on to cane trash in cisterns and here it gets sour. Into these cisterns sludge settling from the fermented wash is from time to time put. This acid when fit for use smells like sour beer. Flavour is prepared by running fermented rum cane juice into cisterns outside the fermenting house along with cane trash and dunder that has been stored from a previous crop. Generally a proportion of liquid from what is called the ‘muck hole’ is also added to this cistern. The components of the ‘muck hole’ are the thicker portion of the dunder from the still, the lees from the retorts, and cane trash and other adventitious matter which from time to time finds its way into this receptacle. From this cistern the incipient flavouring material passes on to a second and third cistern filled with cane trash, and to which sludge from fermenting wash has been added. From the third cistern it is added to the wash. Skimmings are run from the boiling house into cisterns half filled with cane trash. This is allowed to remain four, five, or six days. When the skimmings are considered ripe, wash is set up with them. Fermentation lasts seven to eight days. The time which elapses between setting up the wash and distillation is from thirteen to fourteen days.”

25. W. I. B., VII., 141. (this might refer to the Wochenschrift fur Brauerei journal but I’m not positive)

For Sale: Counter Pressure Keg-to-Champagne Bottler ($225USD)

**Award winning** Bryn Tattan just used the Keg-To-Champagne bottler to take top Boston prize for the Bulleit Bourbon cocktail contest and is now going on to present her drink for 450 people (10 gallons!) in New Orleans.

Bostonapothecary is proud to introduce a next generation counter pressure bottler inspired by the infamous champagne bottle manifold. The counter pressure bottler attaches to champagne bottles with the same collar system as the original manifold but also includes a down tube and side port with a second Cornelius fitting for venting or pressurizing. The down tube can also be removed and a check valve inserted to revert the bottling head back to the same functionality as the original design for in-bottle carbonating, reflux de-aeration, or counter pressure to preserve sparkling products.

Counter pressure bottling is a fairly advanced procedure and assumes users are familiar with carbonating in Cornelius kegs. There is not much hand holding here so this product is designed to fulfill the dreams of people who pretty much already know what they want to do and how it will work. This product fills a giant hole in the market. Cheap versions, which don’t handle pressure levels beyond beer (and require two man operation) are available for $70 and then nothing worth a damn is available until $10,000. No other product is available that can give you full control at the smallest possible scales. Though slightly technical, counter pressure bottling is safe and liquid is typical only transferred at under 40 PSI which is a small fraction of the working pressure of Champagne bottles. Transfer pressure, because liquid is only being moved rather than forced into solution, is much lower than the pressures used for in bottle carbonation of the original Champagne bottle manifold and is thus a safer procedure.

setThe down tube has been designed as a standard soda keg down tube to keep all the parts familiar. The accessory check valve (included) is from a Guiness type keg coupler so it is tried and true as well as easily replaceable. The check valve slides comfortably into the specially designed food safe seal which engages the bottle. The functionality of going from down tube for liquid transfer to check valve for various non transfer tasks means the tool can be used around the clock and helps justify owning multiple units. Such versatility is not a feature of any competing product at any price range.

optionsGas can be bled from the bottles with a “key” which is best done with a Cornelius gas quick release fitting with a pressure gauge and bleeder valve (pictured above). This key is not included with purchase but can be acquired affordably from my favorite supplier, the Chicompany. Champagne bottles, such as magnums, can even be turned into mini kegs and a hose can be placed over the down tube to reach the bottom of the bottle. Gas can then be inputted into the side port to move liquid up the hose instead of down. The key can also be used to measure the internal pressure of a keg and when paired with the temperature, can imply carbonation level (a common brewers technique!).

keyinstalledEverything was designed with cleanup in mind which is another major strength over competing designs. The Cornelius fittings hold a seal when only thumb tight so disassembly can be done without tools to maximize productivity. The Cornelius fittings have also been proven to hold a seal for months on end which is the reason for using a second Cornelius post instead of integrating a bleeder valve (yes, I systematically explored and tested every option). As opposed to the bulky, large square footage, standing clamp designs of competitors, the small size and portability of the collar design allows all parts to constantly be dunked in sanitizer for cleaning (parts should never be dish washed at high temp because high heat will weaken the seal of the embedded fittings).

The bottling head features unique over-molding of stainless steel 19/32 fittings for anchoring and an uncompromising seal. This complicated production technique, typically found only in very expensive medical devices, was made possible by developing a new laser cut acrylic mold box & plastic silicon die technique (that I’m very proud of, woohoo!).

molddyes

Production is currently still rather bespoke and all sales are being reinvested into the project to upgrade the designs and manufacturing techniques to take full advantage of CAD, 3D printing & CNC machining (there is finally a legit engineer on the team!). Until further notice, purchasers will be part of an early adopters / patrons of the arts program and entitled to trade in their units towards new versions at the expense of shipping and other greatly minimized expenses (manufacturing techniques allow reuse of the costly stainless fittings). Early adopters will also get the benefit of small amounts of consulting which is basically the ability to constantly pick my brain about product usage and potential applications as well as recipe development.

The design features many advantages over competitors and the number one is portability and the potential to be used 24/7 for a variety of tasks followed by affordability. Counter pressure bottling requires significant amounts of inactive time (due to physics) so it is not exactly the fastest process. The affordability of the design allows users to own multiple heads for the price of a one head system from competitors. This allows users to purchase more heads at their own pace to reduce inactive bottling time. As one bottle is coming to equilibrium and “bonding” so the manifold can be removed without detrimental foaming, another bottle can be filled and maybe yet another can be capped.

Another unique feature is the usage of only Cornelius gas fittings instead of both gas & liquid fittings. Liquid can run through the gas quick release so what this means is the same input at the top of the bottling head can be used to both pressurize the bottle bringing it up to the same pressure as the keg (as well as flush it using the key) and then be used for the liquid line. The liquid jumper cable going from the keg to the manifold will have a liquid disconnect on the keg side but a gas disconnect on the manifold side. This breaking of the rules means the bottler requires less fittings to function and the force to attach the main fitting presses straight downward over the center of the bottle so as not to stress the seal.

With enough early adopters, new tools will be introduced such as a collar to hold 25 mm beer & soda bottles. Working prototypes already exist but need to be scaled upwards to safe, consistent, mechanically precise, and economically viable production.

Distant projects are proposed for affordable but limited production runs of equipment for bottling carbonated water in old fashioned soda siphons. Also a flexible bottling plant has been conceived for eco-hotels and other programs in far flung areas who need bottling heads that can handle the assortment of miscellaneous bottles recycled in their area.

PATENT PENDING

SAFETY DISCLAIMER: USE THIS HIGH PRESSURE PNEUMATICS PRODUCT AT YOUR OWN RISK. WE ARE NOT LIABLE FOR ANY INJURY INCURRED BY THE USE OF OUR PRODUCT. ALWAYS WEAR SAFETY GOGGLES WHEN USING THE MANIFOLD. USE ONLY BOTTLES RATED FOR THE PRESSURE YOUR REGULATOR IS SET AT. DO NOT SET YOUR REGULATOR HIGHER THAN 60 PSI OR RISK WILL ESCALATE. BEWARE OF OUR SEDUCTIVE DESIGN AND MARKETING, THIS PRODUCT IS DANGEROUS AND SHOULD ONLY BE USED BY THOSE THAT FULLY UNDERSTAND THE RISKS. DO YOUR DUE DILIGENCE BEFORE YOU OPERATE THIS PRODUCT.





six new distillation papers from the IRS

unfortunately I only have these as paper copies and cannot scan them as yet.

1941 REPORT ON WHISKEY AND RUM
Valaer, Peter
J. Association of Official Agricultural Chemists (1941), Vol. 24, No. 2, pp.224-231

this paper turned out to be about a new method of determining tannin content for analysts and isn’t too important these days

1937 ACID CONTENT OF WHISKEY
Schicktanz, S.T. and Etienne, Arthur D.
J. Industrial and Engineering Chemistry (1937), Vol. 29, No. 2, pp. 157-159

this paper looks at how the pH of whisky taken by an electrode can be biased by the alcohol content and is still somewhat relevant today. this is another paper about methodologies for analysts.

1945 CARAMEL AND OTHER ARTIFICIAL COLORING MATTER IN ALCOHOLIC LIQUORS
Valaer, Peter
J. AOAC (1945), Vol. 28, No. 3, pp. 467-470

this paper was a new methodology for detecting caramel which can either be lawfully used or as an adulterant. the method was developed as a collaborative effort and was rigorously tested and commented on by numerous analysts across the country.

1956 REPORT ON METHANOL IN DISTILLED SPIRITS
Mathers, Alex P.
J. AOAC (1956), Vol. 39, No. 3, pp. 737-738

this is very brief and is just a comment on new methods for measuring methanol which is tricky due to its similar volatility to ethanol. the paper requests more trials with collaborators.

1956 LABORATORY CARBONATION OF WINE
Etienne, Arthur D. and Mathers, A. P.
J. AOAC (1956)
this interesting paper develops a means of investigating small levels of carbonation that can be left in wines categorized as still as opposed to sparking. this is important because sparkling wines were taxed at a higher rate at the time. the authors build an apparatus similar to my champagne bottle manifold and use a laboratory shaker to agitate the bottles which is similar to my hand shaking method in effect. to measure carbonation they don’t rely on a gauge but rather build a mercury manometer as a more reliable means of measuring small amounts of pressure. this is apparently why pressure can be measured in cmhg or centimeter of mercury as well as PSI or BAR.

1968 ANALYTICAL PROFILE OF CISTERN ROOM WHISKIES
Schoeneman, Robert L. and Dyer, Randolph H.
J. AOAC (1967), Vol. 51, No. 5, pp. 937-987

this extensive paper is pretty much a blockbuster and I definitely need to create a scanning. amazing data I’ve never seen is collected from 85 whiskeys taken from 42 distilleries. no first names are given, even still, the most exciting parts are the tables that report the grain bill, fermentation process (sweet or sour mash), lactic culture added, spent beer used %, gallon / bushel beer yield, fermentation hours, details of the beer still and the doubler, the distillation proof, and the proof of entry into the barrel.

a particularly cool part are the comments from the author on previous studies of the same type and whether whiskeys then (1968) where like those of 1898 studied by Crampton & Tolman. the paper also features a spectacular bibliography with entries I’ve never seen.

A round up of the most current Vermouth literature

A lot has happened in vermouth since Maynard Amerine’s great annotated Bibliography but not much of it has a web presence or even awareness in popular culinary. Most of the great research has been done in India, believe it or not, and is associated with the brilliant Dr. VK Joshi.

The Indian work with vermouth supports my theory that vermouth flourished in the late 19th and early 20th century because people’s tastes were more sophisticated than their ability to create wines. In India, simple plebian & ordinary wines, probably at risk of oxidation, are ameliorated and preserved to become enticing, exciting, and memorable aromatized wines.

I’ll link to and summarize a few of the great works I’ve recently come across from India. I had first come across a paper from India about seven years ago but somehow I’ve lost it and it doesn’t appear in this list so I know this is much more great Indian work out there. I made my first mango vermouth many years ago, but I made the wine myself and I think it had problems I’ve since learned how to correct.

Vermouth Production Technology – An overview This is one of the great concise modern looks at vermouth making. The bibliography is wonderful and there is a great botanical formula for a mango vermouth.

Flavour profiling of apple vermouth using descriptive analysis technique Worth checking out for the spider web graphic of apple vermouth alone. This paper can teach popular culinary a lot.

Influence of ethanol concentration, addition of spices extract, and level of sweetness on physio-chemical characteristics and sensory quality of apple vermouth This is a great paper about refining and optimizing vermouth formulas. In the paper is a dynamite looking botanical formula for apple vermouth.

Panorama of research and development of wines in India Interesting with a lot of amazing ideas. There is a great entry in the bibliography from 1985 “Mango Vermouth – A new alcoholic beverage” that I would love to track down.

Effect of different sugar sources and wood chips on the Quality of peach brandy Not exactly vermouth but interesting for the peach brandy obsessed crowd and beautiful ideas for those making mixed mash distillates.

Production technology and quality characteristics of mead and fruit-honey wines – a review Again not vermouth but included because the ideas are brilliant. There is also a wonderful paper describing the major uni-floral honeys of India. Who would not want to try mustard honey or cardamom or tamarind flower honey?

Analysis of volatile aroma constituents of wine produced from Indian mango This paper gives some great advice about producing fruit wines. This bibliography is interesting and there is a paper from the 1980′s cited about making dessert and madeira style mango wine.

A very interesting book, Specialty Wines Volume 63, has a chapter on vermouth written by an Indian author, among some other cool topics like Vin Santo making and the Appassimento technique. Rumor has it a PDF of this book exists out there on the web.

One new idea explained in this Hungarian paper from 2004 is that vermouth has serious antioxidant capabilities. In vogue extremist adages about the need for absolute freshness of vermouth might be bogus due to vermouth’s being pumped full of antioxidants from various botanicals. I have witnessed this first hand with some of my vermouth making explorations that are now 7+ years old. My Hercules renderings, where I even made my own base wine without reductive techniques, were preserved miraculously well by yerba mate and yarrow flowers. The fruit wine base could never have been expected to live that long without developing an oxidative character but there are a few bottles left if anyone is in doubt. Other papers do exist on the antioxidant activity of wormwood. This paper covers both antioxidant and antibacterial activity.

Besides the papers from India, probably the most interesting modern paper written about vermouth comes to us from the Bacardi Group’s Ivan Tonutti also of Martini & Ross Grand Lusso and Bombay Sapphire fame. Tonutti has become well known as a brand/botanical ambassador, but the paper isn’t well known because it was written for a Brazilian science journal. Wild ideas are touched upon like the vacuum microwave hydro distillation of botanicals. Tonutti has certainly seen some wild stuff and this paper is not to be missed. This article from the Wine Spectator is worth taking a look at and funny enough, Tonutti appears at the end in a field of angelica.

A near term Bostonapothecary project in the pipeline is developing a low cost method of standardizing a botanical change as well as doing reasonable amounts of competitor analysis on a budget. I have done a lot of reading to make it happen and all that is left is to raise some funds for the glassware necessary. I’m slowly developing a consulting package for small scale distillers where we will spend an intensive weekend covering a few analysis and fabrication techniques plus learning how to use the vast collection of literature I’ve assembled.

Another project I’d like to tackle is developing beverage fabrication manuals to help new producers in the developing world capitalize on their assets in the booming craft economy. It would be nice to see areas that produce orange peels also producing orange liqueur instead of merely selling the peels for short dollars while the cointreaus of the world add only a little more value and reap some massive out-sized profits. Organizations like FAO with this handbook are funding such initiatives:

This handbook is part of a series of agribusiness manuals prepared by the FAO Investment Centre Division, in collaboration with FAO’s Rural Infrastructure and Agro-Industries Division. It was prepared for the EBRD Agribusiness team, under the FAO/EBRD programme of cooperation. The production of the manuals was financed by FAO and by the EBRD multidonor Early Transition Countries Fund and the Western Balkans Fund. The purpose of this handbook is to help agribusiness bankers and potential investors in the Early Transition countries (ETCs) and Western Balkan countries (WBCs) to acquire basic knowledge about the wine sector and to become acquainted with recent economic trends in the sector around the world, with a special focus on the ETCs and the WBCs. This volume was prepared by Frederic Julia, Wine Expert, and reviewed by Emmanuel Hidier, Senior Economist, FAO, as well as by members of the EBRD Agribusiness team. Electronic copies can be downloaded from www.eastagri.org, where a database of agribusiness companies, including wineries that operate in the ETCs and the WBCs, is also available. Please send comments and suggestions for a future edition of the manual to TCI-Eastagri@fao.org.

Well-placed Witnesses to Beverage History with Ruth Teiser

Long ago I had read one of these interviews as a plain text file not really understanding what it was. It turns out to be a giant treasure trove of interviews collected by the astoundingly brilliant Ruth Teiser. Lately this blog focuses on distillation and quite a few of the interviews tell the story of distilling in California, particularly brandy. Wine making is also covered but it is important to note that mainly they discuss ordinary wines as opposed to fine wines which there were very few of until relatively recently. Most of the distillates this country made until recently were also intended to be ordinary rather than the super premium we are seeing today. Beverage alcohol, for a long period of our history, was just food and budgeted from the food category as opposed to the larger food + hobby budget category we see today. There is a definite rise of fetish drinking these days and it might actually be a return to fetish drinking that was seen pre-prohibition when imbibers willingly paid particularly high amounts for alcohol.

These interviews should definitely interest the anthropologist. One of the most important ideas to note running through some of the interviews is how the wine industry went from producing dry wines before prohibition to producing mostly sweet wines after. Prohibition had a big role in warping the American palate and orientating taste towards sweetness. It is often thought we are hardwired to pursue sweetness like we do, but it may just be the product of highly malleable culture.

I’ve read quite a few of these interviews but not all of them. In some I learned technical things, in others history, and others still the business. One, Antonio Perelli-Minetti’s, was just a plain thriller and covered everything plus adventure.

“The California Wine Industry Oral History Series, a project of the Regional Oral History Office, was initiated in 1969 the year noted as the bicentenary of continuous wine making in this state. It was undertaken through the action and with the financing of the Wine Advisory Board, and under the direction of University of California faculty and staff advisers at Berkeley and Davis.

 

The purpose of the series is to record and preserve information on California grape growing and wine making that has existed only in the memories of wine men. In some cases their recollections go back to the early years of this century, before Prohibition. These recollections are of particular value because the Prohibition period saw the disruption of not only the Industry Itself but also the orderly recording and preservation of records of Its activities. Little has been written about the Industry from late In the last century until Repeal. There Is a real paucity of Information on the Prohibition years (1920-1933), although some wine making did continue iinder supervision of the Prohibition Department. The material In this series on that period, as well as the discussion of the remarkable development of the wine Industry In subsequent years (as yet treated analytically In few writings) will be of aid to historians. Of particular value is the fact that frequently several individuals have discussed the same subjects and events or expressed opinions on the same ideas, each from his own point of view.”

CALIFORNIA WINE INDUSTRY INTERVIEWS

I think I am slowly going to quote my favorite passages from each link and that will hopefully pull together a narrative.

Interviews Completed by 1988
Leon D. Adams. Revitalizing the California Wine Industry 1974
Maynard A. Amerine. The University of California and the State’s Wine Industry 1971
Maynard A. Amerine. Wine Bibliographies and Taste Perception Studies 1988
John B. Cella, The Cella Family in the California Wine Industry 1986
William V. Cruess, A Half Century of Food and Wine Technology 1967
William A. Dieppe, Almaden is My Life 1985
Alfred Fromm. Marketing California Wine and Brandy 1984
Joseph E. Heitz. Creating a Winery in the Napa Valley 1986
Maynard A. Joslyn. A Technologist Views the California Wine Industry 1974

“Well, I was told very frequently, as appears in my previous interviews, that the big difference between wine making in California pre-Prohibition and post-Prohibition is the fact that the basic principles of wine making, which were traditionally kept as an operating secret by the old winemakers, became so widely disseminated by the teaching and extension activities that largely initially came from Berkeley that knowledge which was available to a few became available to all. This has characterized the wine industry as a whole.”

Amandus N. Kasimatis, A Career in California Viticulture 1988
Louis M. Martini and Louis P. Martini. Wine Making in the Napa Valley 1973
Otto E. Meyer. California Premium Wines and Brandy 1973
Norbert C. Mirassou and Edmund A. Mirassou, The Evolution of a Santa Clara Valley Winery 1986
Robert Mondavi, Creativity in the Wine Industry 1985
Myron S. Nightingale, Making Wine in California. 1944-1987 1988
Harold P. Olmo, Plant Genetics and New Grape Varieties 1976
Antonio Perelli-Minetti. A Life in Wine Making 1975
Jefferson E. Peyser. The Law and the California Wine Industry 1974
Lucius Powers. The Fresno Area and the California Wine Industry 1974
Victor Repetto and Sydney J. Block. Perspectives on California Wines 1976
Edmund A. Rossi. Italian Swiss Colony and the Wine Industry 1971
Arpaxat Setrakian. A Leader of the San Joaquin Valley Grape Industry 1977
Elie C. Skofis, California Wine and Brandy Maker 1988
Andre Teh el ist chef f . Grapes. Wine, and Ecology 1983
Brother Timothy. The Christian Brothers as Wine Makers 1974
Ernest A. Wente. Wine Making in the Livermore Valley 1971
Albert J. Winkler. Viticultural Research at UC Davis (1921-1971) 1973 Louis Roos Gomberg. Analytical perspectives on the California wine industry, 1935-1990 Miljenko Grgich. A Croatian-American winemaker in the Napa Valley.
Warren Winiarski.  Creating classic wines in the Napa Valley 1994

“That was also there. All of those things. We didn’t talk about the major ingredient, the accumulation of scientific information and things that people did at Davis. Maynard Amerine’s work with grapes and where they grow best –that bulletin of the Agriculture Experiment Station at the University of California1 that I used as a Bible, reading it in a devotional way. Every day you read a little bit of this, at night you read a little bit of that, getting intimately immersed in the contents. You read another chapter and tried to figure out what these must analyses could mean and what their significance was. The existence of such a rich body of knowledge was certainly another major ingredient. And I think the other thing was the people, among whom I count myself, whose taste and aspirations were formed elsewhere and who brought in the ability to actually accomplish the coming together of these several elements.”

Paul Draper. History and philosophy of winemaking at Ridge Vineyards 1970s-1990s 1994 Louis Trinchero. California Zinfandels, A success story Margaret and Dan Duckhorn. Mostly Merlot, The history of Duckhorn vineyards Albert Brounstein. Diamond Creek Vineyards: The significance of terroir in the vineyard 2000 Richard Forman. Launching Bordeaux-style wines in the Napa Valley: Sterling Vineyards, Newton Vineyard, and Forman Vineyard 2000
Augustine Huneeus. A world view of the wine industry 1996
Joseph Phelps. Joseph Phelps Vineyards: classic wines and Rhône varietals 1996
Justin Meyer. Silver Oak Cellars: focus on Cabernet Sauvignon 2000