Distillation is a method for increasing the alcohol content (and, thus, the potency) of a liquid already containing alcohol - the existing alcohol content usually the result of the fermentation of vegetable sugars. The distillation process separates the alcohol from other parts of the solution by the heating of the liquid to 173° Fahrenheit, a temperature sufficient to boil alcohol but not water. The resulting steam (vaporized alcohol) is collected and condensed, returning it to liquid form - but a liquid with a much higher proportion of alcohol than before. Repeating the process increases the liquor’s potency yet further. Because distilled alcohol contains bad-tasting and dangerous chemicals called fusel oils (actually forms of alcohol) and congeners, both by-products of the distilling process, it is often aged in a procedure, originating in the eighteenth century, that rids the beverage of these chemicals. As the liquid ages, its container (preferably made of wood) colors and flavors it to produce a smoother and better-tasting product (Ray 1974).
A constant theme in discussions of distilled liquor is that of fire, which has three different metaphoric meanings. First, beverages are “burnt,” or distilled, over the flame of a still. Second, although it is a drinkable liquid, distilled alcohol is capable of combustion. The third meaning is an apt description of the sensation experienced by consumers of distilled spirits.“Firewa-ter,” aguardente, aguardiente (meaning rough or burning water), and ardent (burning) spirits are all terms referring to such a sensation (Needham 1984).
Stills are the traditional equipment needed to distill alcohol. There are many different types. The earliest known is the ambix (plural ambices) used by Greek alchemists. Ambices were ceramic or metal pots with heads shaped so that liquid would condense inside the head and drain out through a collecting tube. Later, during the Middle Ages, Muslim alchemists, who also employed the ambix, added the Arabic article al - to its name, hence the term “alembic” for a still (Forbes 1948). When larger amounts of alcohol began to be distilled in the fifteenth and sixteenth centuries, the ambix was improved, giving rise to several types of stills.
A common one, the pot still, dates from the sixteenth century. The fermented beverage is boiled in a large pot having a curved top that allows the steam to pass to a coiled cooling pipe called the “worm,” in which the vaporized alcohol condenses into a liquid. The distillate then flows from the worm into a receiving vessel. Pot stills, like those used in the sixteenth century, were later carried to the Americas and to other European colonies and remain in use in traditional distilleries. In Europe and the United States, pot stills are employed for the production of such beverages as French brandy, Italian grappa, and Scotch whiskey (Maresca 1992). The liquids produced by a pot still at the beginning (termed “foreshots” by. American distillers) and end (“aftershots”) of a particular distillation are undrinkable or, at least, foul tasting because of the fusel oils that they contain and are consequently either redistilled or discarded. The liquid produced in the middle of the distillation process is the valuable fraction, and proper separation of the liquor from the by-products requires both experience and skill.
The early nineteenth century saw the invention, by Aeneas Coffey, of a still that permitted more or less continuous distillation (Forbes 1948).This device consisted of two hollow metal columns through which vaporized alcohol rose to condense on metal plates. One column served for distillation and the other for rectification - a process of adjusting the potency of an alcoholic beverage, often by redistillation. But because distillation was continuous, the Coffey still did not permit the separation of the bad-tasting beginning and end by-products from the vital middle of the run. All of it tasted the same, being of uniform but lesser quality. Today, such mechanical stills can process thousands of gallons of liquid at a time, but pot stills are said by many to produce better-quality beverages.
Redistillation is sometimes called “rectification,” but this is an ambiguous term, which, legally, can also mean blending one distilled beverage, or “spirit,’with other spirits or flavorings. In many cases, tasteless neutral spirit becomes an esteemed beverage with a little help from the rectifying process; examples include some Scandinavian akvavits and Polish vodkas (Grossman 1989). Spirits are also blended with water to make them drinkable.
World History
