Die Fabrikation des Jamaika – Rums und des Batavia – Arraks Deutsche Destillateurs Zeitung

What I’m presenting here is a massive 14,696 word research paper from 1936 on Jamaica rum and Batavia Arrak translated from German. This was beyond the reach of the U.S. library system and getting it was only made possible with the help of Stephan Berg from The Bitter Truth. If you need a video metaphor for the relentless pace of the ideas presented, here is a trailer:

It never stops and you must decompress afterwards. It certainly teaches something about Jamaica rum and Arrak even if nothing is very certain, but it also walks us through the cast of scientists that worked on these problems. In the case of Jamaica rum, they were building it while in the case of Arrak, they were merely trying to understand it. These guys were giants of their centuries and Eijkmann even went on to win a Nobel prize (for discovering vitamin B). By the end, two science systems are even pitted against each other. The Chinese, who run the five Batavia firms, built their system which is arguably superior to Jamaica rum without science as we neurotically know it. Our science cannot exist without being written, such as in the article, while theirs, which is Eastern or we could possibly even say indigenous, cannot exist without being continuously taught. This is all wildly important to the new spirits industry which should be existing in an in between space I call guided traditional practices.

Enjoy.

Die Fabrikation des Jamaika – Rums und des Batavia – Arraks
Deutsche Destillateurs Zeitung

The fabrication of Jamaica Rum and Batavia Arraks
German Distillers Magazine

Part 1 of March 7, 1936

An overview of the most important original works, especially English and Dutch researchers.

The production of the especially in Germany and England preferred Jamaican Rum, the German Rum and the Flavored Rum, is still unclear to today’s day despite all attempts. The information disseminated in the literature is often based either on deliberate misleading or on complete misunderstanding of the economic situation. Since Eugen Sell’s 1890/91 works published by the imperial health department showed his excellent treatise on “cognac, rum and arrack” at the time, not much has been discovered in German, apart from analytical investigations of the finished product and attempts to which were carried out here in the country e.g. by Herzfeld. Considering that a major literary source of Sell’s was the book “The Bengal Suger Planter” by S.H. Robinson, published in 1849 (!) In Calcutta, it is easy to conclude that since then a lot has changed and must have come to light. Sell’s statements should not be repeated here. The publication of a detailed description and critique of the mycology of tropical noble brandy, which I intended a few years ago, has been called into question for personal reasons. Collected, in my files, is an extremely important material and should be made more accessible to German science and industry than was previously the case. These fundamental works are by no means new, but have become known to us only in very narrow circles. This is because they are written partly in French and English (Rum), partly in the Dutch (Arrak) language. In those days, it was very time consuming to bring the works together. I owe a lot to Rum with the help of the Department of Agriculture in Washington, which is otherwise known to be helpful. Other, partly more responsible Departments of the producing countries failed unfortunately. Either they completely owe the answer or did the work in question with an unmistakable gesture. Whether economic considerations played a role may be left out. The Dutch sites (Arrak) were much more responsive than the island Americans. The Dutch researchers answered in the most amiable and detailed manner, so that I think I can give more information about Arrak than about Jamaican rum. In spite of everything, the following collective report will spare future researchers trouble and show some direction.

[SELL E. . Üeber Cognak, Rum und Arak. Arbeiten aus dem Kaiserlichen gusundheitsamte (a) 6 (1890), p. 335-352 ; (b) 7 (1891), p. 210-252 ; (c) Sonderdruck;

Herzfeld A. Bericht über die Versuche zur Darstellung Rum-artiger Produkte aus Rübensaft, Melasse und Rohzucker, Zeitschrift des Vereins für die Rübenzucker-Industrie des Deutschen Reiches 27. N. F.; 4o (1890), p. 645-680 ; Oest.-Ung. Z. Zuckerind. Landw. NF 20 (1891), p. 124-128.
Report on the attempts to present rum-like products from beet juice, molasses and raw sugar, Journal of the Association for the beet sugar industry of the German Reich]

RUM.

Considering rum, that thousands of smaller and larger distilleries (very many sugar cane farms distill themselves) produce rum, but only a very small number are able to produce the rum that is paid the most because it has the purest and most flavors, that is very noticeable. Everyone has the same sugarcane as their starting material, all work in the same climate, machine manufacturers would certainly like to supply the same equipment used by one to two dozen manufacturers of primary goods, and yet only these few distillers produce anything other than that cheap Antilles rum, Cuban rum, Nigger rum, Demerara rum, or whatever else it likes to be called, which is usually a bit of a pleasant drink whose enjoyment is based entirely on its alcohol content. The Englishman Percival H. Greig from Westmoorland, who had heard of the great successes of the pure culture propagated by the Copenhagen bacteriologist Hansen in 1892/93, and of the great importance which the various breeds of yeast have on the aroma of the alcoholic liquids produced, did quite rightly. He decided to go to Jamaica to study rum production at the source. Before that, he went to Copenhagen to work for E.C. Hansens, H. Jörgensen, who dealt specifically with yeast cultures, to take a course and to prepare for his practical task scientifically. He not only studied Mycology in general, but Prof. Jörgensen approached him together with the rum problem. They brought Molasses and Dunder from Jamaica, with whom they carried out the preliminary tests in Copenhagen. Each of our readers knows what molasses is. I have to explain briefly what Dunder is.

In the tropical climate of Jamaica, fermentations usually run very stormy and often with strong foaming. This foam is called skimmings. Naturally, it is rich with wax of the sugar cane, and therefore also the essential oil contained in the wax. Skimmings therefore come as much as possible into the still. The main body of skimmings does not come from fermentation. This foam is formed rather in the sugar separation with lime. The sugar cane juice contains about one-quarter percent added lime, resulting in the so-called “ceiling separation”, i.e. a muddy foam goes to the surface with clarification by the juice. It is considered the main source of the aroma. When the clarified juice is then boiled up, in the so-called Clarifyer, once again skimmimgs separate, but are not as muddy as the first contained. Both types of skimmings go as well as the molasses towards the rum distilleries. Of course, each variety remains for themselves, the blends only make it to the still either according to a specific recipe or the circumstances. On this occasion may be pointed to the following. The highest sugar content is in the lowest parts of the sugar cane stem. It decreases steadily towards the top, so that the tips are completely or almost completely sugar free. To separate the juice, the cane stalk is allowed to pass through roller presses. After, the residue is treated with water and pressed again. The remaining residue is called Bagasse. Bagasse is very woody and serves as a firing material [for steam equipment]. Another important part of Rum-Mash is the Dunder. It is the unchanged or still concentrated residue of the still. When considered raw, it can only be regarded as a decoction of the yeasts that have fermented the sugar. Since yeast residue are known as excellent yeast foods, the value in terms of the life activity of the yeasts is clear. It is not clear, however, that flavoring is promoted by Dunder, unless one assumes that the flavoring yeasts thrive particularly well on the decoctions of their own kind. These terms are used repeatedly in Rum and Arrak literature. They therefore had to be described in a more specific and understandable way than was generally the case in German publications.

We are now following the publications of Greig. They begin in a very systematic and content-rich way to suddenly stop. Greig had gone under the Rum Distillers and lost interest in chatting about the subject [Greig developed commercial interests!]. Some things are very remarkable. Before he went to Jamaica, he published in the English magazine “The suger cane” the results of his work at Jörgensen. They appeared on 1.11.93 under the title “Fermentations in Rum Distilleries“. He tells how he came to Jörgensen and worked there. In this situation, it is only natural that he believed that he could find the solution to the rum problem exclusively through the new Hansen principle of using pure cultures. As will be shown at the end, and as especially the excellent Dutch bacteriologists Want and Prinsen-Geerligs have clearly stated (they were concerned with the analogous conditions at Arrak), the presence of certain yeasts (Sacharomyces) is necessary, their total purity is but not only unnecessary, but even undesirable. Greig first emphasizes the extraordinary poverty of the pertinent literature, quoted especially Sell whose work was then new, and again the now nearly one hundred years old Robinson, namely his “Bengal suger planter” from 1849. This supplied him and Jörgensen with the first practical information. In order not to become too broad, we emphasized that he found yeasts of very different kind and effect in the Jamaica-related molasses and the related Dunder. He isolated a large number of these yeasts and allowed them to ferment molasses-sugar solutions. That alone lasted for three months and gave him the right confidence to be on the right track, even if he did not get a final result. Several years later, in 1895, he published several substantial essays after arriving in Jamaica and continuing to work. They can all be found in the Bulletin of Botanical Department of Jamaica, from the Government Printing Office at 79 Duke Street, Kingston Jamaica. Under the common title “Contribution to the study of the aroma in rum” appeared three essays. The first is of a general nature and reports on the rum-yeast found by Greig, first called number 18, later referred to by Jörgensen as Sacharomyces Mellaceus [pretty sure this would later be recategorized as Schizosaccharomyces Pombe]. Then follow “Rum Aroma II, the fruit acids, at the end of this part Greig commits a later regretted indiscretion about certain additives. The third part is titled “Rum Aroma III, Rum Oil and Organic Bases”.

In his first work, Greig attributed the rum aroma mainly to the following five sources:

1.The nature of the sugar cane,
2. The soil on which the sugarcane has grown on,
3. Carrying out of the fermentation,
4. The type of distillation,
5. Storage of barrels, especially at high tropical temperature.

For no. 1, all information are missing, although the point is completely correct. As we learned from the Dutch, there are many hundred varieties of sugarcane. Already around 1890, the experimental station Midden-Java, Semarang, had alone 343 species in their experimental garden, as Winter (Studies on the sugar cane, dissertation Hall 1890) tells, who had worked there as an assistant. It is not to doubt that the variety, as well as the apple or the grape, is of great influence on the aroma.

[We still do not know a lot about cane varieties, but the best present day investigations are being done in Hawaii.]

Also on the important point no. 2 Greig is silent. Every winemaker will be convinced of the importance of the location and the soil.

[I have heard wonderful anecdotes from Cape Verde on blocks of cane well known to produce the best rum and set aside for the distiller himself.]

In contrast, there are very interesting and valuable versions of the yeast. Greig had already found in Copenhagen with Jörgensen, as mentioned, a yeast that seemed to him in relation to the formation of the rum flavor. He says, “It belongs to the top-fermented yeasts, it throws a foam on the surface of the fermentation liquid, which has a nice golden yellow color with molasses and Dunder and is very tough. The fermentation process is slow and takes a long time, depending on the composition, concentration and temperature at which the mash is fermented, about 10 – 14 days. The fermentation is very calm, the gas is released in small bubbles, in some stages, the fermentation is barely noticeable. Although something like “fruit smell” is present during the fermentation, one can not yet speak of a final aroma. But if the fermentation is finished and if you let the liquid rest for about 24 – 36 hours, then you can smell a lovely aroma. To undoubtedly prove that the formed aroma is due to this, the following attempt was made. Molasses, Dunder and water were mixed in the appropriate ratio and sterilized by boiling. The mass then stood to cool on air previously liberated from all germs, and when the liquid had taken in a sufficient quantity of air it was evenly distributed in two fermentation cylinders, which were also sterilized. One was fermented with the particular yeast, which I call number 18, the other with another Jamaica yeast, which I call number 4. The two cylinders were then placed under exactly the same external conditions, and the fermentation could begin. The phenomena in both cylinders during fermentation were characteristic.

Number 18 covered itself with a thick, golden, buttery skin, the fermentation was lazy. Number 4 remained on the ground, the fermentation went quickly and was technically speaking, a “Champagne” – fermentation, which was completely over after just 5 days, while the number 18 still persisted. Number 4 was allowed to stand for 36 hours over fermentation time: no aroma developed. The fermentation at number 18 was over after about 12 days, the liquid also remained for another 36 hours: It developed a strong fruit flavor. This experiment proves that the flavor in question can be attributed to the influence of yeast number 18, since both fermented liquids of exactly the same composition were fermented under exactly the same external conditions …

[Keep in mind. This is all Greig being quoted here and it goes on…]

One confused me for a while: Dunder and molasses with yeast No. 18 gave the flavor, but nutrient salt and molasses with yeast No. 18 did not give it. Therefore, the flavor of yeast # 18 had to be produced by acting on Dunder’s fabrics. But Dunder is just a residue of mash, previously fermented and distilled, in fact, the residue of the cane juice, the skimming and the molasses. But neither the cane juice, which still contains the substances that make up the skimmings, nor molasses give the flavor. Maybe it was then due to the cooking process in the distillation? [if the aroma comes from glycocides, do they accumulate in dunder?]

Accordingly, pure cane juice and molasses were fermented, distilled and prepared fresh mash with the Dunder thus obtained: it developed no flavor! It was apparent from this that the Dunder as such has nothing to do with the formation of the aroma in question. (Dunder is thus a hitherto indispensable nutrient of yeast No. 18!).

While I was busy in Europe with the isolation of various yeasts from the molasses and Dunder sent to me from Jamaica, I searched for a long time in vain for a yeast that would be able to produce a pronounced aroma. From my material, I have certainly made no less than 200 pure cultures. A yeast only attracts my attention as it seemed capable of developing a faint aroma, certainly more than the others. I therefore tested this yeast more precisely. When examining the mix from Dunder and molasses, which I fermented with this yeast, I found it very sour. It was therefore assumed that such strong acidity would be detrimental and prevent logical functions. I therefore neutralized the acidity of the Dunder with a few drops of caustic soda and set aside the liquid that had almost completely fermented the yeast No. 18. After standing for about 3 days the fermentation was over, the characteristic aroma was created. When my experiments in Jamaica showed me that the aroma could not be produced from fresh sugarcane juice or molasses or from sugarcane juice and untreated skimmings or from molasses and untreated skimmings, but from Dunder with yeast no. 18, and since I am partially neutralizing the Dunders sent to me in Europe, I thought of the treatment of the sugarcane juice in the boiling house. Because in Jamaica, the treatment of the sugarcane juice with lime is commonly used. So I made fermentation trials with sugarcane juice that was treated like this. But since an alkaline liquid is unsuitable for alcoholic fermentation, and as the skimmings are brought, if possible, alkaline from the cooking house to the acid fertilizer, I decided, in order to test the efficacy of the treatment, and at the same time a favorable fermentation liquid for the yeast. In order to convert the alkalinity of the sugarcane juice into a weak acidity with sulfuric acid, Dunder naturally was not to be used in these experiments. Fresh sugarcane juice was therefore divided into 3 parts. No. I was made alkaline with lime, No. II was not treated at all and served only as a control, while No. III was not treated with lime, but acidified with sulfuric acid …

[another thing to keep in mind that sherry had a phase of famously being plastered with lime. I think a book I have on Australian wine making at Roseworthy describes it.]

No. I was cooked after treatment with lime to mimic the treatment to which the skimmings in the cookhouse are subjected, and the sulfuric acid was added shortly before fermentation. No. III was boiled before treatment with sulfuric acid to prevent that in case of release of volatile acids they would be expelled by heating, so that the maximum effect would be achieved if any effect by the presence of sulfuric acid should arise. No. II was cooked without any addition. After the three batches were cooked and had been in contact with sterilized air for a sufficiently long time, equal amounts of yeast #18 in pure culture were added to each portion and fermented, with the outside temperature being the same in each case. In Experiment No. I, which was treated with lime, the characteristic aroma was formed; and experiments II and III did not arise. It must be noted, however, that the aroma produced was not very strong, but its presence could not be denied. So here we have the 4 points necessary to produce the flavor in question:

1. The germs: yeast No. 18,
2. The addition of skimmings or sugarcane juice,
3. The treatment of the liquid with quicklime or caustic alkali
4. The time (the liquid has to stand for 24 – 36 hours after fermentation has ended).

[schizosaccharomyces pombe, long chain fatty acids from the wax, a big pH buffer, and a resting period for enzyzmatic action to cleave bound aroma compounds apart. Arroyo briefly explored this resting period.]

The absence of any of these 4 factors is due to the non-production of the flavor in question. I am expressly speaking here of the flavor in question, since it is not intended to claim that no other flavor can be produced by other yeasts that are active in fermentation. In fact, the treatment with lime, for reasons that I will show at another time, has an effect on the aroma of the resulting distillate, regardless of the activity of any yeast …

Although the activity of this yeast is necessary, certain other conditions are equally necessary; the aroma produced during fermentation is the result of more than one factor, but the type of yeast used plays an important role in the matter. I have been able to determine how yeast #18 must be applied to produce the flavor in its highest efficiency. But you will see that I have approached the matter a bit superficially. I have yet to show why the effect from lime by later addition for sulfuric acid is not illusory. Later experiments have taught me with absolute certainty that the skimmings in the vessels must be heated and mixed with lime after treatment so that the lime treatment can effectively influence the flavor of the rum, in any case, whether yeast no. 18 is used or not.

[so is Greig being quoted or does this author in 1936 have access to a sample of yeast #18?]

Part 2. March 21, 1936

In the second part of his essay, Greig discusses the importance of a “fruit acid”. He can not identify them with certainty, but reports that it is evidently the same acid that Herzfeld had found (experiments on the production of rum-like products from beet juice, molasses and cane sugar.) Time magazine of the Association for the beet sugar industry 1890 (Vol 40) p. 645). Unfortunately, Herzfeld did not identify the acid either. It is a fermentation product, which is involved in the formation of Rum-ester. As far as one can get a picture of the inadequate analyzes of Greig, Sells and others, it may be a fatty acid (butyric acid, capric acid or pelargonic acid).

However, it should be noted here already that the possible synthetic composition of Rum-ester would not encounter any serious difficulties if we wanted to produce rum in the country here. What matters most is the so-called essential oil, which is the main constituent of Rum-aroma. In particular, I remind all analysts that the best way to determine if you are dealing with genuine rum or essence is to let a sample stand with sulfuric acid and then determine by sensory examination if there is any odor after a certain time is left or not. The esters are destroyed here, but the constitution still unknown rum oil remains. So Rum-essence becomes odorless, so to speak, while the real product or a blend of it still has the unmistakable odor of rum.

[this is a test I’m trying to revive and I think I’ve found a good protocol. Arroyo described it a little too loosey goosey.]

Rum oil should therefore not be an ester. It can therefore only make Greig’s”fruit acid” of minor importance, although of course it is well known that the esters in the rum are not worthless for taste and smell.

[rum oil!]

Lint-oils [fusel oils?] of various kinds, such as amyl alcohols, which effectively act as a reinforcing base for the essential oil, are certainly also produced during rum fermentation. This is the meaning of Greig’s fruit acid.

Greig reports:

I first discovered this acid in old Dunder, where it was abundant. Dunder contains at least as much as I could tell from the smell at the end of the campaign, not from the acidity. It did not appear until a vinegar fermentation took place and large amounts of “vinegar nut” appeared in the liquid. After a while, the vinegar smell became less intense ….
The fruit smell then came out strong. When I extracted Dunder with petroleum ether, a fragrant residue remained after evaporation of the solvent. After the addition of caustic soda, the odor disappeared instantly, but reappeared upon addition of sulfuric acid. It is therefore evident that the substance has an acid nature. The question now was how does this acid get into the Dunder? It was not in it when the Dunder was freshly prepared, it was found in considerable quantity after the end of the vinegar fermentation.

I ignore Greig’s explanations because they are uncertain. It may be similar to butyric acid fermentation. After the lactic acid fermentation of sugar has ended, that is, after the lactic acid bacteria have abated, butyric acid bacteria now find favorable living conditions and form butyric acid until they too run out of required food.

Exactly so may special bacteria (because it is probably a biological process) form the “fruit acid”, after acetic acid bacteria have been degraded in the Dunder. Apparently, the presence of a particular nutrient is required, which is located in the Dunder and comes either from the yeast or the molasses or the sugarcane juice. To realize that would be a worthwhile task. However, it can also be a lime-decomposable glycoside-like or, as greig means, ester compound in the sugarcane juice. Because Greig continues:

When I added dilute sulfuric acid in the cold to sugarcane juice, I was unable to detect fruit acid. Otherwise, if one takes into account the treatment of the sugarcane juice in the cooking house, i.e. heating with a little bit of lime. I then heated sugarcane juice with lime and then acidified it with sulfuric acid. The smell of fruit appeared, and an extract of petroleum ether left a residue which had the same fruity smell as the fruit acid extracted from the Dunder. It can therefore be concluded that we are dealing with the same acid. My explanation of the formation of this fruit acid would therefore be that it is first associated with an alcohol in the sugarcane juice, that in the treatment with lime a decomposition, saponification, takes place, wherein the calcium salt of the acid arises to release the alcohol. In the following fermentation in the cane juice or in the Dunder, it is decomposed to form free fruit acid and acetic lime. I can not say anything about the binding of fruit acid in the original sugarcane juice. Perhaps it is in the form of wax or oil, perhaps explaining the energy needed to decompose it. It is not doubtful that it can be decomposed directly by strong sulfuric acid without prior treatment with lime and heating. But since this process is not carried out in the brewhouse and a vinegar fermentation can not work as vigorously as concentrated sulfuric acid, it is clear that the treatment of the juice with lime plays an important and crucial role in bringing the fruit acid into a form in which it subsequently becomes a source of flavor. In whatever connection the fruit acid may be, however, it is fleeting at any rate. This seems to me to be an important point, because the volatile compound can escape with too much lime in the form of steam if heated too vigorously, without being decomposed.

[always be buffer-cleaving motherfuckers!]

That this is really possible is shown by the following experiment:
Some Dunder was made strong alkaline and distilled. The liquid was heated rapidly to boiling, distilled off ¼ of the liquid. When the distillate was first reheated with strong alkali and after acidification with sulfuric acid, the presence of fruit acid was shown; Extraction of another part of the distillate without treatment with alkali and acid did not leave any fruit acid.

I have also been able to produce the fruit-ether of this acid in the rum by a treatment with alkali and sulfuric acid, which seems to prove that some of the acid sometimes escapes decomposition. It therefore seems to me proven necessary to convert this “salt” into a form in which it can subsequently form a source of the aroma to heat the cane juice for a moderately long time to a temperature not exceeding 80 °C. If the fire is too strong, there is a possibility that a considerable amount of the salt escapes with the steam and thus escapes the reaction. However, as far as the fruit acid is in the form of its calcium salt, it can not have an aroma-producing effect. It therefore requires acidification by sulfuric acid or vinegar fermentation in order to be set free. It is therefore evident that it depends a lot on the treatment that the liquid experiences afterwards in the brewhouse.

When the “ordinary” or “pure” process is used, that is, a quick, pure alcoholic fermentation takes place, no fruit acid is liberated, and one misses the aroma it produces. However, if the skimmings are allowed to run over so-called “waste cisterns” filled with waste sugarcane, where they undergo a preliminary acidification, which is certainly a vinegar fermentation, then the fruit acids are liberated, provided that the heating with lime in the cooking house is carried out effectively. The nature of the aroma produced is likely to be different, depending on the diversity of the handling of the waste cisterns. As we learn from reports by the Dutch researchers, the waste cisterns often play a slightly different role than Greig’s terminology. There is a disease of sugarcane, which is called pineapple disease. It is that certain black molds no longer affect healthy cane parts; the mold can not harm healthy stalks.

F.W. Went reported in the Bulletin of the West Java Research Station, Surabaya, in 1893, that he had discovered a new fungus inside cane stalks, which was significantly affected by the release of a strongly ethereal odor reminiscent of pineapple. He called this bacteria Thielaviopsis aethacticus. It grows on solutions of cellulose or starch without producing this odor. But in solutions of dextrose, cane sugar, and also dextrin, the fungus, possibly after previous inversion, produces alcohol, acetic acid, ethyl acetate, and pineapple ether. The latter disappears but with longer exposure again! The mushroom does not affect the healthy sugarcane because it can not penetrate through the hard bark. But if the bark is damaged, or if the cane is peeled, infection occurs.

[F.W. Went is pretty obscure and does not even register in Olbrich bibliography.]

From the Arrak distillers, we know that they have special cemented cisterns containing such mold-seeded sugarcane, which must properly yield its pineapple flavor. These cisterns are called “waste cisterns”. Greig says that “the nature of the aroma produced differs, depending on the diversity of how the waste cisterns are handled.” Since fermentation is rapid in tropical countries, all preconditions are given to bring such by-products of fermentation or flavoring ingredients in alcoholic solution and abase the alcohol in the distillation of course [wording here is terrible]. He says, for example: “There is no doubt that many types of fermentation are playing simultaneously in the waste cistern; the fruit acid will endeavor to esterify with the alcohol in the status nascens [some translation issues here possibly with transposing the original text] and to form their characteristic esters. Leave the liquid in the fermentation tank until a “creamy” foam forms.

At the end of this part of the essay, however, Greig draws a remark from the pen which corresponds to what material experts have always assumed and which is never mentioned again either by Greig (apart from the third part of the same work) or by other authors: the Flavor influence by vegetable or other additives. He concludes this second part as follows:

As fruit acid is present in considerable quantity in the sugarcane juice, it can be liberated by the ordinary processes of the cooking and distilling house and greatly influence the character of the rum. It would be interesting to know whether the fruit acid is present in the sugarcane juice of all farms and all varieties. It may be that the sugarcane of different soils or different types of sugarcane from the same soil produce different aromatic acids. So, in different rums, I could discover my own smell and take off with petroleum ether, which reminded me of new leather, and it may be that the smell is caused by the presence of an acid in the rum, which has this flavor. This can only be decided by a prior analysis of a cane juice from possessions that produce rum with such leather odor.

The smell of leather can also come from artificial aromatization, because there is a wood in Jamaica, which has a smell strongly reminiscent of new leather and is able to release its aroma to the rum when it is soaked in it.

About this wood I have tried to make inquiries at a large number of botanical gardens in the tropics, of course, first in Kingston. All in vain! Most of them did not answer at all, some answered briefly, they knew nothing about it. The gentlemen from Jamaica wrote that Greig’s opinion was wrong.

[Crabe writes to tell us he has found the name of the particular tree described in a French work by Duplais:

“Most of the liqueurs of the islands which come from Martinique, Guadeloupe or Barbados, are prepared with aromatics taken from the plants of these countries, such as tulip tree bark, aromatic canang or Ethiopian pepper, avocado tree which smells like anise, Jamaican balsam tree which smells like roses, the narrow-leaved dodo tree which smells like pippin, and a host of other ingredients which are very little known to us, but whose sweet smells make them sought after to Europeans.”

A. balsamifera L. Jamaica]

However, his statement is too definite and too obvious. In addition, we are well aware of scents from all kinds of drugs by serious reporters.

It is permitted to quote here also a German expert, the deceased privy councilor Herzfeld from the sugar institute in Berlin, which, relying essentially on Stohmann, in the already quoted work the following informs. He complains, first of all, that “the scanty works about rum fabrication unfortunately often suffer from obscurity and manifold contradictions”. Then he continues:

In order to give the rum aroma, many additives are made in the distillation, such as in Madagascar shamrocks, in Asia e.g. Acacia bark, called Pattay, in eastern India and St. Domingo leaves of Annona squamosa; peach leaves that hide unpleasant odors are especially popular.

He had to base his description of the production on the Robinson book of 1849 (same as Sell); because he had not found something more up-to-date. In this connection, it may be anticipated that a relevant paper by the French author Georges Jacquemin (Comptes rendus hebdomadaires 1897, vol. 125 p. 114 [scroll up a bit, fascinating]) entitled “Développement de principes aromatiques par fermentation alcoolique en présence de certaines feuilles” (Development of aromatic principles by alcoholic fermentation in the presence of certain leaves). The only short work is very interesting. Jacquemin says the following:

The leaves of many plants with characteristic tasting fruits do not suggest that they are the source of this taste. If you grate them between your fingers or crush them in a mortar, you will not notice any smell or taste; if one cooks the leaves with water, one does not notice anything either.

These properties of certain leaves, which are not to be noticed by any physical means, seem to me to play the role attributed to them in the maturation of the fruit, and they may be compared to glycosides. Guided by this presupposition, I have carried out the following experiments, which serve as the point of departure of others, the result of which I will submit to the Academy.

I submerge, for example, leaves from the apple tree or pear tree in a 10-15% sugar solution and then add a yeast or a Saccaromyces, this selected to cause a fermentation of a bouquet. Once the fermentation is under way, a smell of apples or pears becomes noticeable, depending on the lineage of the leaf. As soon as the fermentation has ended, after removal of the yeast, a more or less straw-yellow liquid is obtained, which reveals the characteristic taste of the fruit and results in the distillation of an alcohol with a fine bouquet of apples or pears or grape vine leaves give a liquid of a distinct vinous smell and taste and in the distillation of an alcohol of fine bouquet. These experiments are made with grape leaves of my own estate in Malzeville near Nancy, which gives a wine of not special flavor …

After this digression we return to Greig’s work. It is, despite all the ambiguities that are probably due to insufficient scientific, especially chemical, education, the most revealing of all Jamaican rum works, though necessary to read them critically.

Part 3 – March 28, 1936

In the third part of Greig’s work (published January 1896), which he calls “The Rum Oil and the Organic Bases”, he probably corrects some of the meanwhile recognized errors, but also shows that he was attentive and clear minded, the essence not to understand the recipe for the whole thing. As you know, there are “recipes” for everything. They may also be meant quite honestly, but their value always remains very limited. Every industrially experienced man knows this. A sausage recipe, which gives impeccable goods in Berlin, for example, is already in need of much improvement in Munich, and something that only arouses headache in Vienna. So it is everywhere, where not working with certain chemical bodies.

Greig as an intelligent, purposeful man therefore does not give any prescriptions, only he seeks principles, in part, with excellent success, to explore. He says in the third part the following about rum oil, as he expresses quite true. He has the appreciative taste even when no recipe to publish, as he happens to find the recipe-based description of a “distiller from Jamaica” who had published an article “How to make German rum” in an American almanac a few years before Greig’s work. In his related article of August 1895, “The Jamaica Yeasts” (Jamaica yeasts), he is content to describe with (well-understood) satisfaction, as the unnamed Jamaican distiller describes the course of the fermentation just as Greig describes it his yeast no. 18 (Sacharomyces mellaceus Jörgensen) was observed and self-described. The anonymous author of the article “How to Make German Rum” was honest enough, just as hinted above, to say that his “recipe” is not always successful, because some distillers did follow to the letter, but they did not receive “German” rum. It’s because not every cane and every dunder or skimmings are the same, just as you can distill every wine, but you do not always get a usable wine distillate.

As we will see later, Greig also considers the development of pineapple flavors organically (by microbes), as already described. He says in the third part of his essay:

Every distiller knows that a rum made from fresh sugarcane juice lacks a pronounced flavor, unlike that made from skimmings, molasses and dunder. It is also commonly claimed that “rum” can only be made from juice or from the residue of juice when they have gone through the process of sugar-boiling, although it was not previously known which special part of this process is the one that matters influence.

My experiments have led me to the fact that heating the juice with lime is the essential part of the process.

I have already shown the role that lime plays in the production of fruit acid, although it is likely that the mode of influence is different than I first stated. Experiments (which are not yet completed) seem to show that the fruit acid is an oxidation product of the essential oil. In any case, observations that extend over a considerable period of time, e.g. the fruit acid from cane juices treated with alkali and then sterilized increased considerably when exposed to sterilized air. This change, whatever its nature, occurs in both alkaline and acidic solutions, although the change in the first case is not recognizable until the liquid is acidified. The action of the lime is in this case a precondition, acting indirectly; but the lime also has a direct impact on the aroma by liberating the rum’s essential oil. (Greig seems to suggest something similar, as the butyric acid fermentation only proceeds well when the precursor lactic acid is pp. – bound.) It’s very easy to prove that once it’s found.

Greig now describes his experimental setup:
The consideration that led to the Enlightenment was:
1. the use of alkali to bring yeast # 18 to the development of its characteristic aroma,
2. the impossibility of obtaining any aromatic oils from untreated sugarcane juice or from rum made only from such sugarcane juice,
3. the discovery of this essential oil in rum produced in the ordinary way
4. That the treatment of juice with lime is some of the chemical treatment that the juice undergoes in most of the country’s factories.

The smell of the essential oil is best described when it is said that it is the essential oil of the rum, because it has the typical and unspecified rum odor. The rum aroma is certainly due only to the presence of this oil’s characteristic aroma, which is so extraordinarily different from that of any other brandy. A small amount of the oil can be left in a glass of air for a considerable time without losing its fragrance. So I have to say that the rum owes it its oily nature, its content and the richness of its flavor, which alone distinguishes true rum from any artificial product ….

It has long been known that a large amount of wax is present in the cane juice, and palmitic acid has also been found in rum (Mulder, Jahresbericht für Chemie, 1858, p.302). However, it seems to lose a lot of aroma oil during manufacture, as it is water-soluble and can not be separated by a process of purification… [the author kind of seems to be plagiar-quoting Greig here and probably throughout the text but its kind of hard to understand because I cannot look at the original document and see its fonts and formatting.]

The boiling point of the oil seems to be relatively high. It passes to the distillation with the last faction and can be extracted from Dunder in considerable quantity. I also managed to extract it from the molasses in small quantities …

The fact that its boiling point is high and that it can be extracted from Dunder also shows immediately that our distillation process does not give us as much oil in our rum as we would like. It also seems to emerge that the use of continuous apparatus with good quality Rectifying column certainly means a reduction in the rum flavor, as far as the essential oil is concerned. It also suggests why lower-level alcohol ferments produces better rum than a very high-fermented one, which seems to be at least a fairly common opinion among growers. On the other hand, one must take care that the lime is not present in excess as this would lead to a decomposition of the “fruit ether”. (Greig should have discovered how much free acid must remain, because the mash must not be alkaline.) It is interesting, it seems that in some parts of the colony it is almost the same, although instead of lime common salt is used, it seems.

[I’m not sure about the science behind using common salt.]

What I said earlier about the possibility of the occurrence of different “fruit acids” in different types of sugarcane and on different soils, also applies to rum oil. I would like to believe, after examining the rum from different farms, that the deviations with the exception of perhaps the “new-leather-smell”, which are not found by the presence of some substances that have this flavor and which are not found in other rums , is more due to the quantity of oil than that different soils each deliver a different characteristic oil.

But once these two important points have been established, namely the necessity of heating with lime to liberate the essential oil, and the amount in which it occurs varies so greatly, we are now able to develop a systematic one to carry out investigation of sugarcane juice of different soils with the aim: Which reason is the difference? [he is describing a future that we have yet to reach.]

It is clear that until the time when it was realized that such differences were occurring, investigations in this direction could not be undertaken. It may come as a surprise to some that such distinctions show no major differences in the quality of rum from the same estate. But the truth is that at the type of fabrication such changes in character of juice and the rum made from it are barely noticed. [so multi variate it hurts!]

As far as the distillery is concerned, not only the liquid of the previous residue, i.e. the Dunder, but many owners pick up their Dunder from campaign to campaign. As far as the distillation itself is concerned, it is not just a two-fold practice. They also uses a retort that still contains some vinasse from the previous distillation. Finally, rum is stored in quite large barrels until it is transferred to Puncheon. Nevertheless, careful examination of the rum does not overlook the fact that there are differences, and differences in the quality of one and the same estate have often been noted in the same shipload.

Excessive treatment of the juice with lime often exerts an unfavorable influence on the aroma and taste of the rum. It is attributable to it when organic bases or bodies of alkaloid nature are set free and found in the rum. Such a rum sample shaken out with chloroform left behind, together with the essential oil, the residue of which the mal-odor masked that of the essential oil and resembled the smell and taste of the dark brown liquid found in the stalk of a stinking tobacco pipe. There is little doubt that this is due to the presence of a pyridine-based base, and that it is the presence of these bodies that makes some rum inedible. Who has the opportunity to smell these bases, separated from the pleasant smelling components of the rum, must have the desire to eliminate them. That you can do that is not doubtful.

If one treats sugarcane juice with increasing amount of lime, one will find that the malodorous parts can only be removed if no considerable excess of alkali is used, and that it is possible to use only moderate amounts of lime, only the essential oil of the rum alone to be set free, without the bad-smelling bases. It can be seen, therefore, that the proper treatment of the liquid is of great importance not only for the sugar maker but also for the rum maker. On the basis of my investigations I can say: If you add so much lime to the juice until its fiery orange-red color turns ruby ​​red, then there is a danger that the stinking bases will be set free. Caution with the addition of lime is therefore essential.

On possessions with heavy, poorly drained, clayey soil, it is considered necessary to take more lime, which is probably related to the destruction of glucose, which is found in greater quantities in a sugarcane of such soil, to which the conditions for maturation of the sugarcane is missing. In addition to the aroma, the organic bases also have a strong inhibiting effect on the fermentation. In a large number of fermentation trials with yeast no. 18, I found that was always true. The yeast is poisoned! The amount of lime not only has an effect on the aroma, but also on the progress of fermentation. It is likely that some failures in the rum distillery can only be attributed to the treatment of the cane juice.

Lime therefore exerts a powerful influence in both good and bad sense. With careful tempering (alkalisation with lime) one will find that the alkali gradually disappears with progressive warming. It is important to pay attention to the different properties of the two indicators phenolphthalein and litmus. The former clearly shows the progressive decrease in the amount of alkali, whereas with Litmus one might think that it is still present in excess. The fact that this is not so, also shows the distillation: one finds that the distillate litmus is bruised and without influence on phenolphthalein. This, of course, is attributable to the cleared volatile organic bases that do not interact with phenolphthalein. It hardly needs to be said that this is not due to the release of ammonia.

[we need better understandings of how construct buffers, what exactly is in them, and how to measure them (pH versus titratable acidity). they may not have had pH yet in 1936.]

Since these attempts are new territory, it was more important to identify the main points of interest and the important facts than to be on theoretical questions. The experiments had been started with the aim of elucidating the role of yeast No. 18 in producing the characteristic aroma. But I soon found myself groping in the dark until I realized the importance of the lime treatment of the cane juice.

In the next work by Greig, “The Jamaica Yeasts”, quoted above, after describing the completely similar fermentation process in yeast no. 18 and the statements of the unnamed distiller from Jamaica, he says that he has isolated and tried about 19 varieties of yeast for Rum. Nos. 1-17 were bottom-fermented, while Nos. 18 and 19 were top-fermented yeasts, aroma was produced only by No. 18. Greig complained that the unnamed author said nothing about the role of “rum fat” nor even the presence of this “fat” mentioned. He then goes on to say: “I have seen a microbe that could develop from pure sugar a liquid that smelled like pure pineapple essence, and I have two types of Sacharomyces anomalus in my possession that produce pronounced pineapple flavor in molasses.” He comes then to the experiments of Dr. Nathan in Rottweil to talk about fruit tastes and pure yeast culture, which he quotes from Hansens “Investigations from the practice of the fermentation industry”.

The remainder of the paper only states that Yeasts 3-17 (see above) finished the fermentations in 3-6 days, whereas Rum No. 18 took 12 full days. Incidentally, Greig recommends the use of pure cultures.

In the last work, which belongs to this, “pure yeast cultures and general considerations”, which also appeared in the Bulletin of the Botanical Department, Jamaica Vol. II, in 1895, general fermentation-biological and fermentation-technical problems are discussed. The topic of “rum” but Greig was too busy and he could not come back to it again; he discusses the relative sterility of a single component of the Rum mash (sugarcane juice, Dunder, Skimmings, Molasses) and concludes that the culture yeast as he wished to use it would not present any particular difficulties.

Incidentally, Greig makes a big difference between “Quality Rum” and Common or “Clean Rum”.

For the “Quality Rum”, which primarily includes the German Rum or Flavored Rum imported almost exclusively by us and in England, he emphasizes the indispensability of the “waste cistern” that has already been mentioned. He calls them directly a “conditio sine qua non” for the production of quality goods. But he does not say enough about the most conspicuous name “trash” cistern.

His undoubtedly correct opinion can be summed up by the fact that the production of the valuable rum aroma involves two factors:

1. the rum oil, which owes its origin to a yeast (Nr. 18 or Sacharomyces mellaceus),
2. the specific rum esters, which are also biologically essential in the waste cistern.
He says even more: “I understand that a rum of a special kind, which for a few years brought a high price, lost it, although its character and quality did not deteriorate. I think “Pineapple Rum” and “New Leather Rum” are the examples.”

As Greig states, the men in the practice say that in the waste cistern the liquid rots, ripens or decomposes which he thinks is correct. Nevertheless, he does not yet have the real nature of the waste cistern (see above the results of Went) yet recognized.

Of all those who have so far published research on rum, Greig has undoubtedly been the best editor. His publications, which were supplemented only slightly by others, would put us in the position, though not, as Herzfeld and others have tried, to produce rum from foreign material without importing alcohol. This means that we could produce rum in the manner of German rum, if we bring in certain raw materials that we can not produce. Perhaps there is still an opportunity to go into the details of this.

What else is published about Jamaica rum, was partly already mentioned. It must be sufficient to refer to the following bibliography, because otherwise this overview would become too extensive.

To conclude our reflections on Jamaica rum may be drawn to the work of the Englishman W. Collingwood Williams, which he wrote in 1907, 15 years after Greig’s work, in the Journal of  the Society of Chemical Industry (p. 498). He did not mention Greig’s work and did not know it. His work even contains an indication that is wrong with regard to fermentation. He briefly says the following:

There are two main types of rum:

1. Common Clean, the ordinary drinking rum,
2. Flavored or German rum, which serves only for blending.

Both have as starting material:

1. Molasses,
2. Skimmimgs, i.e. the skimmed-off foam of the sugar cane juice and then subjected to acid fermentation,
3. Dunder, the distillation residue, the vinasse. It still has 10-15% sugar, larger amounts of organic acids, mainly: acetic acid, propionic acid, butyric acid, lactic acid.

During the fermentation, which lasts 5-6 days (instead of twice the time according to Greig), the acid bacteria multiply constantly and eventually overgrow the yeasts. In the distillation, usually in ordinary alembics over open fire, the first portion forms the rum. In the production of Flavored the raw materials are added to “acid” and “flavor”.

In Trinidad and Demerara, the production of rum differs from the Jamaican method in that only yeasts, not bacteria, participate in the very rapid fermentation. The product is lower quality.

However, Williams has some comparative analyzes that are considered more valuable than his manufacturing data.

[here (p. 771), is a different version of Williams below chart and if you scroll up the pages, there are some stunning illustrations of rum stills.]

	Common Clean		Flavoured		Demerara Rum
	Durch-schnitt	21 Analysen	Durch-schnitt	2 Analysen	Durch-schnitt	21 Analysen
Alkohol….Prozent	79,1	68.6 – 82.1	77,3	66.1 – 80.6	—	—
Extrakt…..Prozent	0,43	0.01 – 1.16	0,31	0 – 0.61	—	—
*Gesamtsäure -1	78,5	30 – 155	10,25	45 – 145	97,5	71 – 123
*Flüchtige Säure -1	61	21 – 146	95,5	39 – 137	53,3	33 – 75
*Ester (als Essigester)	366,5	88 – 1058	391	76,85 – 1204	58,5	37 – 96
*Höhere Alkohole -2	98,5	46 – 150	107	80 – 144	—	—
*Furturol	4,5	1 – 11,5	5,2	2,7 – 120	1,87	0,6 – 27
*Aldehyde -3	15,3	5,0 – 30	20,7	13 – 37,5	—	—

1. as acetic acid
2. as amyl alcohol
3. as acetaldehyde

• grams to 100 liters of alcohol

Before turning to the second part of our theme, the Arrak, a short essay on the so-called yeasts in East Asia may be found here. According to the general state of the art, these so-called yeasts are complicated mixtures of all possible plant components. What the essence of these mixtures was (or is) remained quite unknown to the Arrak distillers. In general, their practical success was enough. Only the Japanese were undoubtedly far ahead of the other East Asians in that, long before Pasteur and Koch, before Hansen and Jörgensen, they knew how to gain and use a kind of pure culture. Of course, they did not produce batavia arrak, but arrak and other spirits par excellence. Arrak is nothing more than a name for spirits in the East.

The first researcher to pursue the fermentation and fermentation processes in East Asia in a scientific and unsuccessful manner was the recently deceased bacteriologist Calmette, director of the Institut Pasteur in Paris. At a young age he was a garrison doctor in Saigon in Indochina, where he also headed the local branch of the Institut Pasteur.

In 1892, in the Annels de l’institut Pasteur, Vol. VI, p. 604, he published his work on Chinese yeast, which is extremely interesting and worth reading even today, under the title “Contribution a L’étude des Ferments de L’amidon”. It describes the nature and use of this so-called “yeast” as well as some related Asian products, which are also used for the alcohol recovery, e.g. the koji of the Japanese. [someone that loves me will translate that]

One year after Calmette, Vordermann published in the Geneeskundig Tijdschrift voor Nederlandsch Indie, Vol. 33, Lief. (Batavia at Ernst & Co.) His also very readable Analecta from the field of luxury foods. He also describes a number of these strange fermenters, including the Ragi (the name is certainly associated with “Arrak”, for which it is also used) and the Tapej, which is particularly useful for the production of rice wine. But he also gives a description of the arrak production Chinese style, which of course, is useless in Germany.

[The Analecta continues for 40+ pages and appears to have some very significant thins about Arrak. This definitely needs translating!]

Through the mycological work of Calmette, Vordermann, Went and Prinsen-Geerligs and Ejkmann we know well today about the actual fermentation pathogens, but the last secret, the Chinese have yet to preserve. Because not the large, modern and rationally run numerous arrak distilleries are the manufacturers of the sought after Batavia arraks, but 5 Chinese companies that are not operated on bacteriological principles and do not meet our ideal of order and cleanliness, but for generations in the possession of the secrets are inherited from the father to the son and outsiders so far unattainable. But this lack of accuracy according to bacteriological views need not be a reproach. It is even likely that the Batavia arrak would cease to be as sought after as it is now, if the absolute pure culture would rule. Something similar we have already seen with the rum. Saccharomyces mellaceus Jörgensen alone does not do it, other microbial beings have to help!

[this paragraph is simply incredible! 5 Chinese companies?]

The essence of fermentation has been clarified by Calmette, the main source of the aroma being found by Went and Prinsen-Geerligs in the Saccaromyces Vordermannii, named by them in honor of Vordermann. However, the quintessence of the scientific work remains the insight that one receives only a very clean industrial spirit as soon as it is worked according to European and especially bacteriological principles. But Batavia arrak can not be made that way.

I now only treat the main works and first report on the so-called Chinese yeast and its varieties.

Calmette first discusses the Japanese Koji, which is preferably used for the production of rice wine or rice beer sake. He continues:

In China and Indochina, different kinds of wine and brandy are produced from rice with the help of a much stronger ferment that has been wrongly thrown together with koji. In the sparse works in which it was mentioned at all (This complaint about “scanty literary sources” is common to all investigators, as it is common to all researchers.) This ferment, consisting of the symbiosis of a mold and several sorts of alcohol-fermenting yeast, saccharified cooked, strength very energetic. Its manufacture is the monopoly of a small number of Chinese industrialists: the indigenous schnapps distillers are absolutely unfamiliar with its production. The Europeans know them under the name “Chinese Yeast”. They are commercially available in the form of small, flat cakes, about the diameter of a 5-franc piece, with a grainy, gray-colored surface. The underside is covered with fragments of rice husk (peeling waste). The smell of this yeast resembles that of moldy flour paste that has been sprinkled with cinnamon or similar spices. It is made according to a complicated recipe, the text of which I was particularly fortunate to get, in Chinese. A number of 46 drugs are listed in it, almost all belonging to the aromatic spices, ginger, pepper, cardamom, cinnamon cloves, etc. but the actual effective principle that saccharifies the starch is not mentioned. We need not be surprised, because the Chinese do not know about ferments and because they probably did not even try to explain the causes of rice fermentation…

Sadly, Calmette did not publish the complete recipe.

It is not excluded that the so-called Chinese yeast in addition to the mold, Calmette Micor Rouxii, also directly transmits flavors. The effective mushroom does not come from the spices but from the rice bran. There are several notes on the production that may soon follow. Common to all is the primitive-looking way of making.

Calmette says

The 46 aromatic plants are first crushed very finely in a mortar, then sieved. The resulting powder, whose odor is very penetrating and pleasant, is poured into a round container and mixed with equal parts of rice flour. The repeated sifting of the mixture makes the mixture very homogeneous. They then put it into a bowl, where it is kneaded with water to a paste of soft consistency. One then rolls from this paste small breads, which are externally infected on mats with small amounts of moistened paste. These balls are kept on covered straw mats in a dark place. After 44 hours at a temperature of 30°C, as they are in Saigon, the development of the germs finishes. The moist paste has taken on a foul smell and is covered with a kind of very fine white velvet. Put them in the sun until they dry completely, then put them in sacks and sell them to the distillers. In many yeast factories, the number of plants is reduced to 10-12, all aromatic, because the others are not so easy to find in the market. They have no other purpose than perfuming the rice alcohol anyway. (The aromatic constituents mentioned by Calmette are already mentioned above.) The Chinese prefer Cochinchina rice with the name Nêp, whose grain is dull white and much more tender and starchy (80-83.6%). For 100 kg Nêp you need about 1½ kg of Chinese yeast. Of this, about 60 liters of brandy are obtained at 36%, that is H. on average 18 L r.A. [some characters here could not be deciphered]

Nêp is Oryza glutinosa, the sticky rice.

Vordermann describes two varieties, Ragi and Tapej.

Ragi.

White, floury ball, flattened, about 3 cm in diameter, which are used as yeast dust and are offered throughout the bazaars and in the Chinese shops for sale. The preparation is of Chinese origin. For this you need in Buitenzorg:

1. saccharum offincinarum (yellow sugarcane); of this you take 3 internodes (stalk compartments), preferably of the lowest part, which has the most sugar;
2. Alpinia galanga, the rhizome of a scitaminee (galangal), in the quantity of a Chinese commetje (about 1/4 L of fluid, filled with the fragments of the rhizome);
3. rice flour, 1/8 gantang (measure for dry goods – approx. 8.5766 L content);
4. Allium sativum, garlic, the tubers of 3 plants;
5. Citrus limonellus hack, so-called blades, half a fruit (a juicy, green, small lemon variety).

Sugar cane and the galangal root are cut into small pieces and dried with the rice flour well in the sun, after which the first 4 ingredients are crushed together to form a pulpy dough with the addition of the citrus juice and a little water. After the course of 3 days, the coarse plant parts are removed, the separated water is poured off and the remaining thick kneaded round to round tubers, which have the shape described above and dried in the sun until they have hardened.

These Ragi tubers are very friable and are later eaten by insects. If a Ragi tube after removal of the dirty outer part in a mortar with boiled and then cooled water mixed to form a thin slurry, and this stored in a covered glass, then in a short time the pulp should be divided into a white sediment and a light-colored liquid. After a few hours bubbles begin to form on the surface of the liquid, which gradually increase. Only after 1-2 times 24 hours the alcoholic fermentation has developed so far that the entire surface of the liquid is taken up by a viscous foam, in which there are small, white sticky islets.

[I have a feeling that above and below are all translated passages from the Analecta.]

Tapej.

Tapej come from 2 forms, depending on whether this substance is used as food or for technical purposes, e.g. For example, in the production of rice wine, Arrak or indigo dyeing in the Chinese manner.

In the former form, it is a preparation of rice, sticky rice, corn or tapioca root. The inconspicuous drug is sold in sealed pisang leaves. The content of such a sheet is partly solid, partly liquid. The solid portion consists of one of the mentioned foods, the liquid portion, which is present in lesser amounts, is a fermented dirty-white juice.

For the preparation of the Tapej, the previously described raw nutrient Ragi, is an indispensable ingredient.

If Tapej is produced, then come on 1 gantang rice or sticky rice 4 Ragi tubes. For the same amount of corn, 2 tubers are sufficient, while for just as many tapioca roots 5 tubers are required. [the logic in here got messed up.]

The main component is first cooked well and then, after all has cooled well, spread on a tetampa (plates with edge) Then it is sprinkled with the ragi, which is finely crushed between the fingers, and intimately mixed. For rice, it is necessary that the mixture is not carried out with the fingers, but with a wooden spoon, otherwise the preparation should easily fail, get sour and could get a reddish color. When the mixing is done, then the whole thing gets moved to an earthen pot, which is placed in a cool place, whereupon everything is covered with Pisang leaves. Then a fermentation occurs, which after 2 x 24 hours is considered sufficient.

The taste is sweet, not unpleasant. Tapej, which serves as food, uses better raw materials than technical ones. This is usually served by the lower varieties of ordinary rice (Siam rice or so-called red rice).

Vordermann also reports in the same work:

The Batavia arrak has always had the reputation of being the best because of its flavor. Its price is therefore higher than that of the coast arraks. The Arrak preparation in Batavia rests entirely in Chinese hands.

The raw material of the arrak preparation is the molasses, “stroop”, which remains in the sugar factories after precipitation of the crystal sugar.

Alcoholic fermentation is initiated by adding tapej of rice after the base has been diluted with water.

The treatment takes place as follows: The raw material is molasses, river water, rice tapej. The process begins with cooking the rice. The rice used is of the lowest quality. In one or more large iron pans the rice is boiled with water (not steamed) so that it is cooked well. Then it is spread out of the pan on plates in a thin layer. After cooling, Ragi is sprinkled on it, the tubers of which are crushed with fingers, and stirred after some hours with wooden spoons to be then brought into barrels, which have openings at the bottom, so that the tapej juice that is forms can run off. They are filled to 2/3, and the contents are covered with a “karong” (jute bag).

2×24 hours, the Tapej must ferment in the barrels, taking into account the temperature conditions; only then is it considered suitable to be placed in a bin that is placed in the air and contains molasses and river water. This liquid has the well-known brown color.

The first day the tapej jelly remains unmixed. On the second day that the tapej has airborne, it is mixed well with the molasses water around it and changed over to another barrel, which is larger, where molasses with water is already in place, so the same amount of tapej acts on a larger Amount of liquid. Nonetheless, fermentation already occurs here.

Only on the third day, after the mixture of Tapej and molasses solution had been exposed to open air for 2 days and protected by a cover against rain, is this sediment, as it is called, transferred to the boilers, the preparation vessels, two large ones Skids, which are placed side by side and on which a third skid stands, the so-called Anstellkufe. This last contains a mixture of molasses with lukewarm water. When the sediment has been brought into the fermentation runners, it can be further filled by opening 2 drainage taps attached to the bottom of the runner, which causes the contents to run aground and mix with the fermenting sediment. Here the sediment remains in fermentation for 4 days. This fermentation is very violent, especially towards the end of time, which remains the approach in these vessels. A reddish-brown foam drifts between the remnants of the rice and the dark brown liquid, and a few yards away you notice a smell of honey and hear clearly the noises caused by the rising of countless bubbles of carbon dioxide.

After the indicated time, the tapej remains are removed and the brown liquid is transferred to small, bulbous jars, which have about 10 liters of contents and are arranged in rows; Here, the upper fermentation stops late, and it is followed by a weak secondary fermentation. The brown liquid remains in it for 8 days, as long as it takes until it is ready to distill. From here it is filled into a simple cauldron by means of thick bamboo vessels, which lead under an overhanging flat vessel to a hole, which is located at the top of the cauldron and which is carefully closed after filling the cauldron.

The boiler is walled in a brick oven; it has a copper helmet, which merges into a metal spiral (cooling coil), which is located in a cooling vessel. By evaporation, the alcohol passes through the helmet into the cooler and is cooled down to a clear liquid, which leaves the radiator as an arrack and is collected in a stone pot, which is built into the ground.

I saw the fabrication process described here in the renowned Khouw Wan Tijang Arrakbrennerei the well-known brand K.W.T) in Kompong Brave in the district Batavia, a factory that dates back to the previous century.

Vordermann then describes the later named after him “flea bacillus”, which he found in the fermenting mash.

The appearance of the flea cells, if I may call them that, happens only in the runner approach, until the molasses comes to Tapej. I never found her in the tapej myself, which I’ve repeatedly examined. Probably the germs are therefore in the raw molasses, and this is likely when you visit the molasses stock of Arrak distilleries.

Which is the reason that the Batavia arrak has a stronger flavor than other Arrak, has not yet been determined. At some place on the coast some time ago, raw materials were brought by Batavian manufactors and then processed there, but the product did not differ from the ordinary arrack made without this aid.

Heckmeyer (instructions on technology and commodities, etc.) (Dutch, Batavia 1876 (by Vordermann as little trustworthy)) indicates that in the vicinity of Batavia (1876), the sugar industry is still very outdated and that much sugar is still in the molasses. That is why you get the best Arrak from these places, which are twice as expensive as the East coast of Java, where you process only very low-sugar molasses.

[Willem Jacob Eduard Hekmeijer]

This bill is not correct. Arrak is not made from crystallizable cane sugar remaining in the molasses. At the most, one could achieve more Arrak, if this cane sugar in Anstellkufen is non-crystallizing sugar or dextrose is changed, with otherwise constant amount of raw material. However, that this should increase the peculiar aroma which the Batavia arrak contains to a greater extent than other arrak, is not inconceivable. Yes, most Batavian manufactories get their molasses from the coast. It is possible that the river water used in Batavia has an influence on the strong aroma, as it is claimed. For the time being, this puzzle still remains unresolved.

After that we return briefly to the Chinese yeast. Their meaning is not limited to putting Sacharomyces Rouxii, isolated by Calmette, in the rice porridge to saccharify it, but it also gives the arrack aromatic components. The same feeling had Calmette and the Dutch, especially front man. The following original recipe for Ragi originates from the former director of one of the state research laboratories in Java, Prof. Eijkmann, mentioned by Vordermann:

30 garlic bushes
20 pepper
2 pieces of cinnamon of finger length
2 finger lengths galangal root
700 g rice
1 cubic meter (69cm) sugar cane
warm water

The preparation is done like this: The rice (certainly unpeeled) is finely crushed with the other ingredients. The sugarcane should be roasted the day before and peeled just before the preparation and cut into pieces. This sugarcane is added slowly during mashing. When everything is fine enough, it is sifted and kneaded with warm water to a dough. From this one forms balls of plum size. When preparing you should beware of drafts. The balls are then placed with a layer of ash of rice straw as a base on a tub and also covered with such a layer. Finally, they are smoked with sugar cane residue (bagasse) for 3 days and dried in the sun.

Based on the information provided by Calmette, Vordermann and Eijkmann, the following composition can be defined for Chinese yeast:

Chinese yeast
20 parts galangal root
5 parts garlic
5 parts ginger
5 parts of cardamom
20 parts cinnamon
10 parts cloves
10 parts pepper
8 parts nutmeg
10 parts anise
7 parts of Roman caraway
20 parts freshly squeezed lemon juice
100 parts rice flour, from unpeeled rice
Water as needed.

The study of Batavia arrak production has attracted a number of Dutch bacteriologists and mycologists with dedication to good results. Vordermann’s work has already been discussed, especially F.H. Went, H.C. Prinsen-Geerligs and Eijkmann. Even the bacteriologist E. de Kruyff, like the aforementioned researchers in the production area, has dealt with the mystery that still surrounds the Batavia arrak. De Kruyff’s work dates from December 1909 and is written on Java in Buitenzorg.

The end result of all research is that although a particular type of yeast produces the basic flavor, it is true that the vegetables of the five Chinese distillers undoubtedly added before distillation have not yet been detected. For the rest, the “waste cistern”, as we shall see, plays the same role as in rum.

Eijkmann confirms the findings of Calmette (Amylomyces or Mucor Rouxii) and Vordermann (flea-bacillus, Saccaromyces Vordermannii Went & Prinsen-Geerligs) in his purely bacteriological work “Microbiological on the Arrakfabrikation in Batavia” (1894). However, the most comprehensive works are shared by Went and Prinsen-Geerligs- teil, some of which are separate. In 1894 a joint paper was published in the “Archief voor de Java-suikerindustrie” “On Sugar and Alcohol Production by Organisms in Connection with the Utilization of Waste Products in Cane Sugar Production“, 1895 a joint paper “Observations on the yeast species and sugar-forming mushrooms of the Arrakfabrikation” [I did not find this one, but I bet its there somewhere!] In the “negotiations of the Kgl. Academy of Sciences in Amsterdam”. Here the work is published in German, after having appeared in Dutch in Java and English in “Sugar Cane” [I looked through the Sugar Cane and did not readily find this]. In 1905 Prinsen-Geerligs published in the “Archief voor de Javasuikerindustrie” a treatise “The Quality of the Java Arraks“.

It is noteworthy that Sell (1891) also complains like Prinsen-Geerligs (1905), that apart from the already cited works “further nothing in the literature can be found on this subject”.

Went and Prinsen-Geerligs first noted (which is well known) that Java produces essentially 2 qualities of Arrak: the common Coastal Macaw and the Batavia arrak. Like Vordermann, they discovered that the essential constituents of yeast in Batavia arrak are the flea-bacilli discovered by Vordermann, Sacharomyces Vordermannii, but that Monilia javanica plays the main role in the not-so-expensive coastal era.

The work of Prinsen-Geerligs (1905) “On the quality of Java Arraks” goes into great detail about all the raw materials. In summary, the following can be deduced from this research: The arrak species also differ analytically from one another, Batavia arrak has e.g. much higher levels of aldehyde and esters. The abstract work of de Kruyff contains this information also.

De Kruyff attributes the different composition not only to the various microorganisms that ferment the molasses, but above all to the different composition of the raw materials.

At that time (1905), the Batavian Arrak distillers obtained their molasses from the Tangerang sugar factories, and since they worked very primitively, the molasses was much less de-sugared than those obtained by the coastal distillers from the large factories in Cirebon and so on.

Since then, the conditions in the Tangerang have become quite different: the Chinese sugar factories have been received, as a result, the Arrak distilleries now derive their molasses from the coastal areas without exception. However, despite about the same operation and now the same raw materials, but still the quality difference between Batavia arrak and the coast arrak persists.

The smell of the more exhausted molasses of the big factories has not had the slightest impact on the taste of the Batavia arraks.

The cause was sought in mycological area, but as we saw, not without success. After all, what remains is the importance of the secret additives that the five Chinese companies make before distillation.

An Arrak distillery in Batavia consists of 3 departments:

1. the yeast production,
2. the premises where the mash is prepared and the fermentation takes place,
3. the distillery.

The yeast production

As raw material for the yeast fabrication serves glutinous rice (Oryza glutinosa), preferably of the lowest possible quality. The rice is cooked in large open pans with continuous stirring on a fire and then spread to cool. During cooling, the rice becomes infected with all kinds of germs. When the rice has cooled, a certain amount of agar balls is powdered and intimately mixed with the rice. On 40 Katjes rice you need 10 Ragi balls. The mixture is then transferred to tall, double-bottomed pots, the top of which is best made of gauze. It is first given a mat, and then the rice mixture is placed on top of it. If the pot is full, then the rice is covered from above with a similar mat. The importance of the lower mat is to prevent the falling through of rice through the mesh, which prevent the upper, the evaporation as much as possible. The rice remains in these pots for two days, after which the cake is brought in its entirety to the fermentation vessel.

During these two days, rice has undergone a number of bacteriological processes, with various organisms present in the ragi being able to develop. As a result of rapid growth, the temperature in the rice rises sharply, to 50° and above. If the height of 50° is not reached, the starting yeast is discarded! So obviously a primitive selective method, because many microbes die at this temperature.

Preparation of the batch and fermentation

The raw material is the molasses obtained from Cheribon (see above). It is in the dilutions, which are used here, a little favorable to the development of microorganisms substrate, bacteria and mold grow poorly due to a high content of solutes in it, even for yeast, the molasses is not an ideal breeding ground, mainly because of their alkaline reaction , To obtain a quick fermentation, as e.g. in ethanol factories, the molasses must first be acidified.

[What is described above is osmotic pressure, for the high level of solutes which can select for alt yeast like Schizosaccharomyces Pombe. Many funky named yeasts have been mentioned throughout this document, but I’m pretty sure that most all have been reclassified as Pombe.]

For the Arrak production now, just as for the rum preparation, a slow fermentation is necessary. The slower the fermentation, the more by-products are produced, and the type and quantity of by-products determines the quality of the arraks.

In the Batavian Arrak Distillers, a more concentrated approach is used right from the beginning, and as fermentation progresses, concentration is occasionally increased. There are two reasons for this: firstly, by constantly refilling, one has the prospect that fermentation can not take too rapid a course, and second, the acids formed are neutralized again and again because molasses is alkaline.

[Fascinating! they maintain their pH by adding more molasses! Arroyo was very big on adding more molasses during fermentation, and these guys have arrived at the same conclusion much earlier. Also, remember up above that alkaline treatment is credited with releasing aroma.]

In the first batch 40 liters of molasses and 160 liters of water are added: for this, the rice is added from the pots. After 24 hours, a clear fermentation has occurred, then the batch is transferred to a second fermentation vessel with the addition of 224 liters of molasses and 672 liters of water. Here again the approach stays one day and then comes into a high fermentation vessel in which it is simultaneously freed by a sieve from the floating solids. Then add 200 liters of molasses dissolved in 280 liters of water. The next day another 200 liters of molasses are added, but no water. Then everything will remain without further additions. After 3 days, the main fermentation is over.

For subsequent fermentation, the solution is transferred to unglazed, round stone pots. The pots have a content of only about 20 L. The secondary fermentation lasts 9 days. The whole process in the Batavian Arrak Distillery takes about 18 days, namely:

1st and 2nd day: preparation of the yeast,
3.-fifth Tag: fermentation in the yeast pots,
Day 6: Seven of the approach, [I think there are translation problems here]
6th – 8th day: main fermentation in the fermentation skids,
9th – 18th day: post-fermentation in the pots,
18th day: distillation.

As already discussed, there is little prospect of overgrowth by bacteria or other undesirable organisms during the main fermentation. The matter is different in the secondary fermentation in the pots, during which no more molasses is added. As the yeasts produce acids, the alkaline reaction gradually turns into an acidic one. Unfortunately, once this is the case, the liquid is a suitable breeding ground for various groups of bacteria, e.g. for Granulobacter and Saccarobacter.

If that happens, you get too little alcohol. Pots with such a failed fermentation can be recognized by the fact that the upper edge looks dry, not damp, as in well-fermented. As the secondary fermentation progresses, the alcohol content increases and the yeasts slowly die. On the 18th day, fermentation is barely noticeable.

Distillation

18 days after the rice has been cooked for the yeast batch, the distillation is carried out. The pots are emptied into a suspended bamboo line that flows above a still. The cauldrons are cylindrical and have a slightly arched bottom with a tap to drain the distillation residue. The kettles are walled in as far as possible and are heated by an open fire. The still head is made of copper and is airtight with clay puttied on the boiler. The still head terminates in a long, spiral-shaped tube that passes through a pool of water, the radiator. This “Rauhbrandkessel” [rough fire boiler] is as simple as possible. Dephlegmation and rectification are not performed. The distillate is collected in different fractions in wooden barrels. The first fraction has a strength of about 50% alcohol, the following are getting weaker, so that one last distillate has about 8% alcohol and is also cloudy. The fractions below 50% are poured together and come in the so-called distillation still. This is just like the Rauhbrandkessel and is only needed to transform the weak Arrak in high percentage. Even the 50% Arrak, the first fraction, is not strong enough, because trading requires 60-66%.

The bacteriological data by de Kruyffs about his experiments are of no interest. On the other hand, the work of Went and Prinsen-Geerligs are more informative, as these researchers were bacteriological and mycologically exact, but they do not describe the technical precedence as much as de Kruyff, but referenced in this respect, whose also only brief information already in discussion the so-called Asian yeasts are communicated.

From the work of Went and Prinsen-Geerligs, published in 1894, one can still see the following: Arrak is produced by fermentation of sugary liquids; For this purpose, mainly molasses is used on Java, from which no more sucrose crystallizes out. It still contains

25-40% sucrose
8-16% dextrose
6-16% fructose

A finer kind of Arrak is made of rice, mostly from the so-called glutinous rice, Oryza glutinosa. To convert the rice starch into sugar, no diastase is needed, but the same substance, which also contains the yeast, which is used for alcoholic fermentation. This stuff is called Java Ragi …
As it seemed that the rice was the main thing here, we tried making ragi from rice flour with some sugary water …
The organisms of the Ragi can be found on rice straw. We were able to isolate them all from this material. The other additions are probably only to produce a nutrient medium.

In discussing the physiological properties of Saccaromyces Vordermannii, the two researchers report that fermentation takes place in solutions of maltose, raffinose, levulose, dextrose, and sucrose, which is first inverted by the yeast. In liquids containing 9-10% alcohol, fermentation ceases. During fermentation, besides alcohol and carbon dioxide, glycerine and succinic acid were also formed. When the alcohol was distilled off, we obtained an arrack with a very fine smell and taste. This arrack contained a little aldehyde and 0.113% ethylacetate (ethyl acetate), but no free acid, nor methyl or amyl alcohol.

[This above paragraph about what sugars the yeast ferments is important because you cannot exactly identify a yeast just by looking under a microscope. You have to give it some simple trials and that helps with categorization.]

Let us point out that Sacharomyces Vordermannii is of concern, since, when working with pure cultures of this kind, it is possible to fabricate a very fine arrack that is not fusel-like, while the arrak of trade always contains some fusel oil. Fermentation proceeds rapidly, in 3-4 days, and about 18-19% of sugar is converted to alcohol and carbonic acid.

However, the demand for using pure cultures was later abandoned for reasons similar to those of rum, because a mixed culture proved to be more convenient because it was cheaper.

There are still two important publications by H. C. Prinsen-Geerligs to report briefly. In his treatise “Fabrication of Rum and Arrak” published in the French language, he once again describes how Batavia Arrak is made exclusively from sugared molasses without further additions,
To catch up is still the indication Prinsen-Geerligs that the fresh air in Java has a temperature of 30°C, which is probably to be considered. He tells in more detail how the Saccaromyces Vordermannii is the sole producer of the Arrak flavor and how, as a result of more favorable growth conditions, this fungus has the upper hand, especially the Monilia javanica, the main fermenter of the Coastal Macaw, that is, the lower variety. He also points to the use of waste and damaged sugar cane plants as far as rum is concerned (waste cistern), but denies their use for Arrak.

He also says that he has not observed or heard of the use of herbs in the production of Batavia Arraks, but he adds cautiously that such use could nevertheless occur. In particular, he explains the frequent claim that cinnamon apple leaves are used as unbelievable because they have no particular odor.

On the other hand, reference must be made to the work already discussed by Jacquemin. After that, many leaves, when present during fermentation, give the aroma of their fruits to the later distillate.

The last publication of Prinsen-Geerligs dates back to 1905 and was published in the Dutch language under the title “The Quality of the Java Arraks” in the Achief voor de Java-suikerindustrie. It was manufactured at the Sugar Cane Research Station in West Java “Kogok” in Pialonga. [Kagok-tegal]

The work is predominantly analytical, but still shows in many places the familiarity of the author with the Arrak production. He also explains the difference between the rumors of arracking. The molasses (final molasses) for rum are pure sweet, with no bitter taste, of a light brown color and have over 50% sugar. The java loaves, however, are as de-sugared as possible, dark in color, sticky and due to alkaline treatment of juices bitter in taste.

With such raw materials one must assume that Arrak receives an unpleasant molasses taste, if it is distilled so that all fragrances go over with. If the factories desiccate the molasses as much as possible, one can not ask for a tasty Arrak. So we come to the conclusion that an aromatic and superior product can only be obtained when starting from pure base material (i.e., sugar).

Literature reference
(only work not cited in the text above).

E. A. Pairoult, Le rhum et sa fabrication. Paris 1903. [google full read]

A. Gaber, Kognak, Rum Arrak. Wien 1923

Alberto Scala, Il Rhum e le sue falsificazioni. Annali dell`istituto d´igiene università di Roma, Vol. 17 Serie I, p.160
[This is possibly another citation for Scala:
Scala Il rhum e le sue falsificazioni Annali Istituto d igiene della R Università di Roma vol II serie I pag 159 Scala Sulla determinazione delle]

Rocques, Eaux de vie. Paris et Liège 1913 [Hathi full view]

V. Marcano, Sur la fermentation du vesou de la canne à sucre Comptes rindus gebdom. Vol. 108 (1889) – 955
[this may be it from another publication.]

Georges Jacquemin, Les levures pures de vin en Distellerie Paris 1893.

Lebbin, ein neuer Weg zur Beurteilung von Rum und Arrak. Chemiker-Zeitung 1927 [hathi does not have this but it is easily inter library loan-able if I didn’t already do it.]

Paul Vuillemin, Über die chinesischen Hefen. Zentralblatt für Bakteriologie, Bd. 8 (1902) S. 409-412. [full view from Hathi]

Calmette, La fabrication de alcools de riz. Saigon 1892

H. Neville, Les ferments industriell de l`extreme orient Biologie, emploi et produits. Encyclopédie scientifipue de aide-memoires, publiée sous la direction de Mr. Léauté
Membre de l´institut. Paris 1902

H. Winter, Über das Zuckerrohr. Dissertation, Halle 1891 (bei Herzfeld – Berlin gefertigt).

Y. Shimogama, Über japanischen Klebreis. Dissertation Straßburg 1886

Karl Bachmann, Der Reis, Kultur und Bedeutung, Disstertation, Marburg 1912

Lafare, Handbuch der technischen Mykologie. Jena 1914

A. Calmette, Manuel technique de microbiologie et sèrologie Paris 1925

Alfred Jörgensen, Mikroorganismen der Gärungsindustrie, Berlin (Parey)
Derselbe, Die Hefe in der Praxis, Berlin 1901

Des Tournelles, Lézé et Peret, Procédés de préparation de l’alcool de riz en Cochinichine, Paris 1888

Julien et Champion, Industries anciennes et modernes de l’empire chinois. Paris 1869.

M. Avequin, Über die Wachssubstanz des Zuckerrohrs. Annales de chimie et de physique (1840), Bd. 75, s 218.

G. E. Ritter, Über das Verhältnis der Schimmelpilze zum Rohrzucker. (Aus dem landwirtschaftlichen Institut zu Nowa Alexandria.)

Colson. Vulture et industrie de la canne á sucre aux îles Hawa et Rèunion. Paris 1904

K. Saito, Technisch wichtige ostasiatische Pilze. Mikrokomos (1912), Bd. 42, S 145-150

J. Scott, The fungi of row sugars. International Sugar journal Nr. 166, Manchester 1912.

C. Wehner, Der javanische Ragi, Zentralblatt für Bakteriologie und Parasitenkunde, Bd. VI (1900), S. 610, und Bd. VII (1901) S. 313-326.
Derselbe, Die chinesische Hefe und der Mucor Roucii, Ebend Bd.VI (1900), S. 353-363.

A.F. C. Went, Die Ananaskrankheit des Zuckerrohrs, 1893 Archief voor de Javasuikerindustrie.
[The pineapple disease of sugar cane]

Derselbe, Krankheiten des Zuckerrohrs, Pariser Kongress Juli 190..