Like any other alcoholic spirit, the distillation process is an essential step to whisky production. It is by no means a straightforward and simple one. In his essay, Silvano Samaroli seeks to enlighten us a little about this process.
This process consists of a sort of purification, a word derived from the Sanskrit root "pur" that means "to rid of pollution" .
There are two distinct methods of distillation: the traditional process of Scotch Malt Whisky, which uses two directly fired stills, and another that produces Scotch Grain Whisky by way of a continuous, steam-heated still.
Regarding the latter procedure, there actually isn't very much worth saying. It tends to be generally used for alcohol, and it generates a spirit dull by name and by nature: light, barely aromatic and inoffensive. In theory it would not require any aging, but the law calls for it just like Malt Whisky.
It is not bound to any territory or microclimatic area, and can be therefore produced anywhere.
For this reason, it is not distinguishable from other spirits distilled in the same pot still, such as Vodka. However, Grain Whisky has a reason for being, as we'll see in the chapter on blending (p. 87). But in order to understand the qualitative supremacy of Malt Whisky, just consider that in 1979 a gallon (4.54 liters) of Grain was worth 99 pounds, while one of Malt cost a whopping 230 pounds.
And so we return to the traditional process. Through fermentation, we obtained a liquid with alcohol levels that vary from 5 to 8 percent.
Distillation is the next step needed to boost the alcohol content of the wash. Thus far there has been a long succession of chemical transformations; with distillation, instead, the process is of a physical nature. In other words, a separation of the chemical compounds in the wash takes place, according to their different reactions at the boiling point. With respect to this varied reaction, various portions or phases can be distinguished. In the first part, the so-called "head", elements that boil at lower temperatures are distilled, while obtaining the most volatile substances, but also the most aromatic, often excessively so. Furthermore, a low alcohol percentage may be observed.
In intermediate portions a high percentage of ethanol (or ethyl alcohol) can be found, while in the last heavier and more chemically complex substances remain.
The product of the intermediate phases (the "heart") is collected, while the result of the first and last, the head and the tail, is recycled and goes back into the still to be distilled once again.
Keep in mind that distillation is not a very accurate system because its separation process is based solely on the different boiling points of each substance, some of which do not differ enough to allow for evaporation at the exact moment it's required.
I would once more stress my point of view, according to which man fumbles a bit when he seeks to alter nature, which is why it is essential to make use of his intuition and his experience, an experience which then ended up becoming tradition. Old copper stills are part of this tradition and were once subject to the most meticulous care, often repaired and patched up, and very rarely replaced at all. A new still would have brought on an enormous interrogative at this delicate stage in production.
Distillation is always carried out through two of these copper stills shaped like large onions, so-called "pot stills". The first, which distills the wash obtained from fermentation, has a wider neck, for a rapid evaporation: it is in fact called the "wash still" . The second, which redistills the product of the first still, possesses a narrower neck and is called the "spirit still" , precisely because it gives us the final product of our distillation, namely Whisky. Of course it is only a potential Whisky: it will have to wait for long still to deserve this name. In this state, it is simply called "new filling", an everyday term used in the cask trade, in the sense that this new spirit will soon be taking its place in aging casks.
The still is directly fired over a high flame and, when its walls are hot enough, it is loaded with the wash. Inside, the liquid is automatically stirred to avoid incrustations deriving from sulfurous substances fixed to the copper, which, in the process of burning, would give off unseemly scents to the liquor.
The resulting steam flows up along the neck of the still and, at some point, through serpent-shaped tubes that, being refrigerated, bring the steam back to its liquid state. The liquid is collected in a specific container which is then sent to the second distiller to be adjusted.
After the second distillation, the "stillman", the head of the distillation process, in charge of the burdensome job of choosing the exact moment in which to separate the part to be recycled from the one that will end up as Whisky, operates without having direct access to the distillate. There's a glass walled, brass container, the "spirit safe", through which the operator observes the distillate as it flows from the second pot still and, with the controls arranged outside, collects the spirit or redirects it to the spirit still. The keys to this case are held by local customs officers, who will in fact heavily tax the alcohol that derives from this distillation.
The spirit safe is equipped with a hydrometer for measuring the alcohol percentage, and a device that allows the stillman to dilute the Whisky with distilled water. Generally the alcohol content is considered ideal once it reaches 25-30 degrees over-proof, which correspond to 71-74 percent of alcohol by volume. Also, if the diluted liquor were to become turbid or display blue veins, it would be considered unsuitable to be collected and left to age.
As you can see, we tend to act more on insight and experience than on prescribed rules. The financial police, on the other hand, who don't care for the quality of the product, follow precise rules by simply measuring the amount of anhydrous liters obtained by the end of the process upon which to apply tax.
Throughout the processes that preceded distillation, a more or less peaty tone along with a couple other aromas were conferred, but the more delicate nuances, the most accentuated tones as well as the harmony of the various compounds, depend on the distiller. In the "foreshots", the head of the distillate, aldehydes and esters, which constitute the most aromatic components, are present, though their excessive presence would not be very elegant nor harmonic in the bouquet, thereby requiring a very prudent dosage.
The distiller builds up the whole framework of perfumes, aromas and body that make up the fabric and bouquet of Whisky. Through the selection of its many components, they imprint a clear and precise personality on the product, an indelible feature that can't be erased nor modified any longer.
But its personality is not everything, and aging will be the final, complementary phase of the production process. The production of Whisky does not end with distillation, as is the case for other spirits, and its process is, therefore, very long.
Although the tone of peat was previously embedded by the process of peating, we should point out that it is mainly made up of a condensation of phenols, also dosed by the distiller, who indisputably has the last word in this regard as well.
I would also like to specify that it is the stillman who determines the quality of a Whisky, although he works on a raw material with a certain predisposition, set by the previous processes, and can therefore be affected by an excessive or scarce presence of selected compounds. Distillation is in fact a physical, and not chemical, operation, there isn't any mutation of matter, only a separation of compounds.
It's now understandable how each production process is particularly incisive on the finished product and must be meticulously executed and coordinated with the others, and not be an end in itself. A small mistake can create disastrous and unrefined effects on the final aroma of a Whisky. Effects whose consequences unfortunately cannot immediately be noticed, but only much later, once the Whisky has matured.
The question remains, then, where unsuccessful Whisky ends up.
Written by Silvano Samaroli
The text is an excerpt from "Whisky Eretico" (pp. 59 - 64), written by Silvano S. Samaroli, published 2017 by The Whisky Library, The Library Group Limited.