GODOY— Manufacture of Sugar Cane Aguardiente, 1916—Brazil

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GODOY — Fabrico de aguardiente de Canna de assucar. Bol. Agr. São Paulo XVII, 694-701, 1916.

This 1916 document may seem unremarkable to some, but it is a glimpse of a transitionary time and from Brazil which I haven’t covered too much. The citation is from Kervegant’s bibliography. An interesting perspective is presented. Farmer distillers are going to do what they are going to do, but the author wants to make them aware of rational efficient processes. About the coolest thing we see is a description of their yeast mash:

They grind a little cane, until they obtain about 50 or 60 liters of broth, adding to this must, sour orange, corn meal, burnt straw, etc., adding this mixture to a fifth and placing it next to the fire so that fermentation can take place more quickly.

Sour orange? which we know would drop the pH, but does it have any relation to the vague “luscious fruits” of the 19th century Jamaica? I was told farmers used (and still do) corn because it is what they had on hand, but I don’t know exactly how they employed it. Straw may be a scaffolding for growth, but what does burning it do? Make it more sanitary? (I know who may clarify these questions.)

Something exciting to see are words in Portuguese that we can use untranslated like cocho for fermentation vat. Cocho could be translated to trough, due to its shape, and likely implies the same engineering as goes into animal feed troughs. Every distilling tradition, across languages is going to have words that should stay untranslated and we should learn what they are so we can celebrate them. Does Bourbon’s yeast vessel, dona, come from the same root as Cachaca’s dórna?

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Manufacture of Sugar Cane Aguardiente and Fermentation Theory

In the belief that I will be able to provide some clarifications to our farmers who, on a small scale, are involved in the cultivation of cane sugar and the manufacture of brandy, I will describe here, although briefly, the manufacture of brandy and the theory of fermentation, as it does not seem out of place to describe rather the routine process that I know, de visu, in use by our farmers so that, when confronted with the rational process, perhaps the farmers can derive some indications that will be useful to them.

Routine process—Grinding the cane, the juice or garapa is conveyed by a spout or pump, depending on the position of the mill, to large wooden containers in rectangular shapes of different dimensions, where it remains for 24, 36 and 48 hours for complete fermentation. In this fermentation vat, or cocho, as the vessel for cane juice is commonly called, upon arrival you should already find the necessary yeast previously prepared for the start of manufacturing, which is done as follows:

They grind a little cane, until they obtain about 50 or 60 liters of broth, adding to this must, sour orange, corn meal, burnt straw, etc., adding this mixture to a fifth and placing it next to the fire so that fermentation can take place more quickly. This yeast thus prepared, is taken to the first vat or dórna which, after fermentation, will provide yeast for the other existing ones. [“quinto” translates to fifth but may imply something else here. Dórna appears to a name for specific vat type and reminds me of Bourbon’s “dona”.]

Some manufacturers save the residue from the vats after the harvest, which will be used the following year to make yeast.

The garapa, after complete fermentation or when it stops, as the farmers say, is again conveyed through a spout and goes to the still where, by distillation, commercial brandy of 20° Cartier [53% ABV] is obtained, more or less.

It is worth noting the absolute lack of cleanliness that prevails in all these operations, as the farmers, not having the necessary knowledge of what fermentation is, leave either the water spouts or fermentation vats completely exposed, from one year to the next. That is, from one grinding to another, not even taking care to apply a syrup when starting a new harvest or making brandy. In fermentation vats placed in the same room as the grinding or still room and completely unhoused, it is not uncommon to find, in the morning, rats that have fallen in during the night; The must from this tank, whether fermenting or already fermented, goes to the still to be distilled. [Where it says apply a syrup, I think that implies already fermenting starter and they are likely derived from cooked syrup or corn meal because no cane has been crushed yet.]

It is easily understood that in a must thus exposed, not only to all kinds of filth, but also to all yeasts foreign to alcoholic fermentation, a good part of the saccharose, which, due to its unfolding through the action of invertin by soluble yeast, should be transformed into glucose and levulose and these into potential alcohol, it is used for different purposes. [This is not rendered the best and the author starts to use the term “soluble yeast” in place of what we now call enzymes.]

Now so that the farmers can, if not completely remodel their processes, at least modify the parts that most harm them, I will take care of brandy manufacture, obeying the rules of modern technology.

Rational process—Spirit manufacture can be divided into three operations that take place in the following order: 1. extraction of the must; 2. fermentation and 3. distillation.

Of the three operations mentioned, the one that undoubtedly deserves special attention is must fermentation; but following the order described, I will say, firstly, that extraction of cane must can be achieved through two processes: diffusion and milling.

The first being not frequently used in small scale industry, we can without prejudice leave it unmentioned. The second, known since ancient times, is completely widespread in our crops; its main part, the mill, is made up of three horizontal cylinders of cast metal, two placed on the same horizontal plane and the third stacked on top of them, keeping the necessary space, which can be adjusted, for the passage of the cane; This process extracts more or less 75% of the sugarcane juice, depending on the perfection of the mill. Modern mills have 3 and 4 sets of cylinders.

Bagasse can be burned, as combustible material, in the furnaces of the stills and boilers, which generally does not happen, as it is common to see on sugarcane farms bagasse thrown near the mills to serve as food for cattle, pigs, etc., or even being thrown into the river if the device is powered by water.

Must thus extracted should be conveyed by the most convenient means, attending the installation of the mill, to the fermentation vats, which should be located in a room suitable for this purpose, known as the fermentation room. These vats are made of both wood and iron; Among us, on small farms, they are only found in wood having the rectangular shape, which is the most common, or the conical shape. Wooden vats have the disadvantage of absorbing a certain amount of must in their walls, which after emptying, acidifies in contact with air and vitiates the must of subsequent loads, resulting in a series of extraneous fermentations and a decrease in alcoholic yield. This problem can be remedied by scrupulous washing and waterproofing the wood of the tank, on the inside, with boiled cotton oil or with pine resin varnish, terpentine, gum lacca and alcohol, in the proportion, respectively, of 4, 5.5, 2 and 16 kilograms. [I’m not quite sure if it should be “terpentine, gum lacquer”.

Vats must be cleaned daily and rigorously with washing, brushing and a weekly passage of milk of lime to destroy foreign yeasts that could penetrate the wood pores. If fermentation purity still leaves something to be desired, then antiseptics are used. For example: calcium chloride in a ratio of 1 to 100. In this case, the vats should not be used without thorough washing in order to eliminate any antiseptic that would harm yeast development. If the vats are unoccupied, it is a good idea to bring them full of water to better preserve them. Iron vats, while avoiding this drawback (the porosity of the walls), present another problem due to the metal’s great conductivity; to expose the fermentable liquid to sudden temperature fluctuations.

As for the capacity of the vats, it varies according to the size of the still, and should always be in relation to the work of the other equipment in the distillery.

The fermentation room should be built in such a way that it has everything required to carry out a good fermentation: a) the temperature must be constant as much as possible, which is achieved, in part, by building brick walls of more or less less thick and avoiding opening windows in the direction of the south wind; b) cleaning must be easy and absolute, which requires the floor to be cemented and with a slope so that it can be washed scrupulously, allowing water to drain easily; c) the internal walls must be cemented up to the height of the vats in order to be washed and whitewashed with the same ease; d) it must be well lit and ventilated so that the carbonic anhydride released from the vats can be easily eliminated, as its accumulation in the vats would constitute an obstacle to the smooth progress of fermentation. In a word: it is essential to keep this room in the most absolute state of cleanliness because this is one of the first conditions for purity of fermentation and obtaining a high alcoholic yield.

I will now discuss, always briefly, the second part of the brandy production: must fermentation.

General notions—The term fermentation is nowadays applied not only to fermentations produced by microbes or figurative yeasts, but also to certain chemical phenomena that are produced no longer under the action of organized yeast, but under the action of soluble yeasts. or diastases, for example: the transformation of starch into sugar by germinated barley.

Therefore, fermentation industries should be considered all those that use the fermentable properties of microbes or diastases; These industries form a very important group that includes distillery, beer manufacturing, vinegar making, cheese manufacturing as well as the manufacturing of certain chemical products, such as gallic acid, lactic acid, etc.

Following a more restricted order of ideas, fermentation industries can be designated as those that put to work the special properties of alcoholic yeasts, and which are therefore based on the phenomenon of the transformation of sugar into alcohol under the influence of yeast. This particular group of fermentation industry, to which the distillery is linked, one of the main agricultural industries, is of capital interest to the farmer.

History of alcoholic fermentation—Alcoholic fermentation has been known for a long time; the Greeks already fermented grape must; the Gauls knew how beer was made, but for a long time they ignored the nature of the phenomenon. Since the end of the 17th century, the scientists Becher, Lavoisier, Guy Lussac, Dumas, Boulay, Caignard-Latour and Liebig dedicated their studies to this phenomenon, issuing the most conflicting opinions, until finally, in 1859, Pasteur came to demonstrate irrefutably that alcoholic fermentation was a vital act resulting from the organization and multiplication of yeast, also demonstrating that all fermentation is a phenomenon that has as its agent a specific organism: alcoholic fermentation is produced by a fungus of the genus saccharomyces (Saccharomyces cerevisiae for cane must); lactic fermentation, lactic yeast, etc. [What is interesting is that these days heritage cachaça fermentations are known for both fission yeast and positive expressions of brettanomyces.]

For spirit producers, not only this microorganism (Saccharomyces cerevisiae), responsible for alcoholic fermentations, is of considerable interest, but also other so-called secondary ferments, such as lactic, butyric, acetic, etc. considered in our fermentation industry as true harmful yeasts; the former, because they transform saccharose into lactic and butyric acids, and the latter because they transform alcohol, through oxidation, into vinegar.

Yeast reproduction occurs through budding and spores; the first is carried out ordinarily, that is, under normal conditions, and the second, by spores, when these conditions cease, three or four globules are then seen to form inside the cells, ordinarily round in shape; These are the species’ organs of resistance to external agents: they are much less sensitive than the yeast itself. When placed in an appropriate medium, these spores thicken, giving rise to a yeast globule, which in turn reproduces by budding.

Physical conditions of yeast life—Of the physical agents that act on alcoholic fermentation or yeast life, heat, humidity, electricity and light, the most considerable, heat, plays an important role in the life of yeast. Experiences have shown us that there is an optimal temperature zone in which the species’ vitality is most active. This optimum zone varies depending on the yeast species; in general it is between 25° and 35°. Below this zone, yeast activity becomes weaker and soon no fermentation is observed. The vitality of the yeast is not affected by low temperatures; only its action is paralyzed. You can even cool the yeast cells for 60 hours at minus 130°, without them losing the power to develop when placed in an appropriate favorable environment.

Neither happens above the optimum temperature; a small increase in temperature immediately endangers the species that supports it, quickly reaching a temperature at which the yeast dies. This increase in heat varies depending on whether the yeast is in a wet, dry state, in globules or spores. Generally, wet yeast perishes at a temperature of 45 to 60°C, prolonged for 5 minutes; in the dry state it resists from 100° to 115°. Spores are generally destroyed at a temperature 5°C higher than that at which yeasts are destroyed.

The second agent, humidity, we can not mention since the fermentable material in question is the cane must.

Electricity and light do not seem to have a specific effect on the life of yeast.

Chemical conditions for the life of yeast—For its nutrition, yeast needs water, hydrocarbon materials, minerals, etc. With all these elements present in cane juice, it can be seen that it is an excellent means for its culturing.

The influence of air on the life of yeast was demonstrated by Pasteur in successive experiments. Thus, in a very airy environment, there is a tumultuous fermentation with a great multiplication of yeast, complete disappearance of sugar and no traces of alcohol appearing. [This would be the difference between growth via respiration versus fermentation.]

In almost anaerobic conditions, fermentation is very slow, the amount of yeast is reduced resulting in gaseous release and the production of a certain amount of alcohol. Conditions in which brandy producers find themselves are intermediate, and therefore the most favorable for its production.

Pure or selected yeasts. There are a large number of different yeasts, distinguished by their particular properties and each giving different fermentation products. There is, therefore, a great practical interest in isolating them, which is achieved by the bacteriological methods of Kock or Hansen; For a long time now, selected yeasts have been on the market that can be purchased relatively easily, which suits the brandy producer, taking into account the difficulty he would experience in selecting them, due to the lack of technique and the lack of a laboratory.

Diastase or soluble yeasts. As stated above, yeasts are divided into figurative and non-figurative; diastases belong to the latter.

Among the food materials attacked by organized yeasts, a certain number are directly assimilable, for example, glucose by yeast; there are others that become assimilable after having undergone a previous transformation; Saccharose or cane sugar, which belongs to this number, is only consumed by the yeast after having been broken down into glucose and levulose, through the action of sucrase or invertin, a soluble yeast with a hydrating action, which is normally found in the canes themselves.

Diastases are unorganized chemical substances secreted by cells, both in higher animals and microbial beings; they are called “soluble yeasts” because a small amount is sufficient to transform large portions of the materials they attack; It is precisely one of the characteristics of soluble yeast, that it presents a large differential between its weight and that of the substance transformed by it.

Heat has a significant action on diastasis; Just as for yeast, there is also an optimal temperature for them, at which they have their maximum action. The temperature at which diastases are destroyed, losing their properties, varies greatly depending on their nature and the state of the humid or dry environment in which they are found; in general they are destroyed at a temperature of 65° to 75°, when they are in aqueous solutions; in a dry state, they easily resist 100°. [Celcius]

Duclaux classifies diastases, according to the actions they produce: diastasis of coagulation, decoagulation, hydration, oxidation and decomponent actions.

Distillation.—The third and final operation in the manufacture of brandy, distillation, takes place when the must has finished fermenting and is no longer sweet, as the existing sugar has been transformed into alcohol and carbonic anhydride. Distillation can begin, which aims to separate the alcohol from the alcoholic solution, which is achieved using devices called stills. These are generally built of copper, containing a boiler (cucurbita), a plate, a coil and a cooling tank. They are so simple and so used in small industries that it is unnecessary to talk about how they work.

From what was explained above, we concluded that the ideal work would be to sterilize the must, then taking it to the scrupulously clean fermentation tanks, then sowing the selected yeast (Saccharomyces cerevisiae, in our case) with alcoholic fermentation free of extraneous yeasts.

We agree that this is not within the reach of the small farmer, but only of large industrial establishments. But the spirit manufacturers, comparing the routine process, which is so flawed, with the rational process to which we refer, will be able to adopt small improvements, such as: scrupulous and absolute cleanliness in the fermentation vats, in the must conductor spouts, and in the fermentation room; waterproof the walls of the vats when made of wood and, finally, purchase selected yeasts from time to time in markets or official establishments to prepare the footings of the vats. These are small pecuniary sacrifices that will be largely rewarded, both in product quantity and quality, which will consequently have better acceptance in the market. —W. Godoy agricultural inspector.