VODKAS

        

Appreciating Subtlety

Despite the widely held view to the contrary, all vodkas are not the same. Qualities and variation from one to another can be subtle, but they are there nonetheless. Think about tasting and comparing one vodka to another, not as comparing apples to oranges but akin to comparing apples to apples-apples of the same variety grown in different orchards with differing geography and under various climate and nutrient conditions. All of these influences leave their subtle mark when the fruit is tasted. Wine geeks would call this the influence of terroir. So it is with vodka-subtle variations, but there nonetheless. Try a blind tasting, and you'll soon see this not-so-plain white spirit in a new light.

The Anatomy of Vodka

Vodka is among the least complicated distillates to manufacture. Its primary influences are the raw materials used (water, base ingredient or fermentable sugar source), method of fermentation, distillation and rectification, process of filtration, and water used as diluent.

  Compared to manufacturing dark spirits such as whisky, tequila, and brandy, vodka production stands out in two distinct ways. First, the distillation process aggressively eliminates elements that influence flavor (often called "congeners"), which can be desirable in other spirits. Second, the final product is free of the considerable influences of maturation or barrel aging. To a large degree, this makes vodka a more exposed, less forgiving distillate, as impurities and imperfections that occur in the manufacturing process are more detectable in vodka than in spirits influenced by the complexities of aging. 

    Distillation and Rectification

In the most basic of terms, distillation concentrates alcohol to a desired level, while rectification serves to purify it.

The distillation process separates components of a liquid mixture by using boiling points. In the case of vodka, the wash's alcohol (ethanol) component is separated from its water component. Alcohol has a lower boiling point than water-meaning, it vaporizes at a lower temperature-so alcohol can be collected separately from the water.

Rectification, meanwhile, refers to the process of purifying alcohol of its unwanted elements. Although the term is more commonly associated with continuous distillation than with pot or batch distillation (read on for this discussion), rectification is, in essence, achieved through repeated distillations, leaving the concentrated alcohol free of waste and unwanted elements-such as congeners (impurities), fusel oils, methanol, and aldehydes that would adversely affect the quality -flavor, aroma and texture-of the final product.

The two basic methods of spirits distillation -pot (batch) and column (continuous)-achieve the same ends and require the same considerable expertise of a Master Distiller, though continuous is arguably more efficient. In contrast to distillation of dark spirits- whisky, brandy, tequila, and so on-vodka distillation aims to get rid of nearly all congeners and leave only the trace amounts needed to express a desirable level of flavor, aroma, and texture. Of note, it is these removed elements that contribute largely to the flavor profile of dark spirits-and likely to the depth of any hangover.

Pot or Batch Distillation

Before the column or Coffey still was invented in the 19th century, distillation was done in a pot still. The pot still, sometimes called an "alembic," was used as early as the third century in Alexandria. This still has two separate chambers-pot and condenser-connected by a tube or swan's neck. Fermented mash, at roughly 8 percent ABV, is poured into the belly of the pot still and gradually heated. Once the temperature of the mash reaches the alcohol's boiling point, vapors rise upward to the swan's neck where the vapors cool. The vapors then begin to travel down the swan's neck into the condenser, where the process of returning the alcohol vapors into liquid form is completed.

The first portion or fraction of pot distillation is called the "heads" and is extremely high in impurities, such as methanol, aldehydes, and esters. The Master Distiller cuts (removes) this portion of the distillate and discards it. The middle portion is referred to as the "heart" and is desirable; the heart is what the Master Distiller works to maintain as the final product. The last portion is called the "tails" and contains unwanted fusel oils and is high in water content; the tails must also be cut and discarded. A single run yields a distillate of approximately 40 percent ABV.

From this point forward the Master Distiller and his proprietary domain rule. The whole process can be repeated many times-by reintroducing the condensate or heart back into the pot for another run-or not at all, as deemed desirable for revealing the heart of ideal quality. Again, ideal is a matter of preference. Fewer runs mean more flavor and character are left behind. More runs yield a distillate of greater purity, flavor neutrality, and increasing alcohol content that could be as much as 96 percent ABV in the end. Rarely consumed at such a strength, the concentrated distillate has to be cut with water, usually prior to the filtration process, to dilute it down to the acceptable minimum bottle strength for vodka-between 37.5 percent ABV (in the European Union) and 40 percent ABV (in the United States).

Pot distillation is usually more labor intensive than column or continuous distillation, particularly if a batch is redistilled multiple times. I argue that where the Master Distiller cuts the heads and the tails is more important than the number of distillation runs. Achieving quality spirit is the main goal and depends on how each producer realizes its desired balance of purity and flavor.

Column or Continuous Distillation

Invented by Robert Stein in the 1820s, the column still was first used in Scotch whisky production. In 1831 Aeneas Coffey earned a patent for his improved version, known as the Coffey still or patent still. Regardless of name, the column or continuous still is made up of two cylinders-the analyzer and the rectifier-placed side by side and connected by multiple pipes. In this system the mash is fed into the still, proceeds through the distillation and rectification process, and transforms into a distillate of desired strength and purity-all in a constant and seamless motion. This efficiency is unparalleled. You could manufacture a greater amount of spirits at a faster speed with column distillation than with a series of sequential pot distillations.

Methods have evolved since Coffey's time, as distillers constantly pursue innovations in technique and equipment. Many manufacturers use still systems made up of several columns to effectively and repeatedly distill and rectify a mixture in order to increase the purity of the final product. It is not unusual for a brand to boast that their vodka has been distilled three, four, five, or even more times.

Dilution

As I mentioned earlier, water is another raw material in vodka production. Most producers insist on using the best quality of water in their vodka-and for good reason. Many vodkas are distilled to 96 percent ABV or 192 proof, but most are sold at 40 percent ABV or 80 proof. To this end, a considerable percentage of water must be added to achieve appropriate dilution and proof.

Understandably, water quality ranks a skinny second to base ingredient quality in terms of impact on flavor outcome. Nonetheless, water is significant as a diluent or to reduce the distillate's proof-say, from 192 to 80. Using anything less than pristine, flavor-neutral water will adversely and significantly affect the taste of the spirit.

Most brands place great emphasis on their water. Manufacturers source their water from proprietary wells, protected reservoirs, springs, lakes, glaciers, or pristine mountain run-off. Others claim their source locations are free of any pollution. Some use distilled water, while some rely on local tap water that has been filtered and purified. Regardless of source, water added to the spirit must be free of minerals, impurities, and other contaminants. Otherwise all time, money, and effort spent producing a quality distillate are wasted.

Filtration

Faith and Wisniewski aptly observe, "Throughout its history ... vodka has been the object of an underlying tension between those looking for purity at any cost and those looking for positive qualities." Filtration helps the Master Distiller achieve the desired levels of purity and flavor, once the distillation and rectification process has removed the lion's share of congeners. Filtration is largely optional, and some vodka producers decide not to employ filtration beyond the function of eliminating obvious particulate matter. Instead, these producers prefer their product to retain some congeners, which imbue the spirit with flavor.Throughout the ages, charcoal or carbon, with its highly absorbent nature, has proven to be among the most efficient, widely-used filtration materials. Preference has even developed for charcoal made from specific trees-pine, birch, poplar, and oak, just to name a few-because of their degree of absorbency. Many producers now use activated charcoal or carbon because its absorbency increases markedly when heated to more than 1,000 degrees Fahrenheit. Once distilled and diluted, vodka is typically pumped through a filtration device (sometimes several) filled with activated charcoal. This process scrubs the distillate of any remaining undesirable particulates, leaving only a pure and clean spirit.

Aside from charcoal, filtration materials and techniques span a diverse range. According to Pokhlebkin, early on vodka producers used "felt of various types; woolen, linen or cotton cloth or cotton wool; paper of various thicknesses and densities; river, sea and quarried sand; (even) broken pottery." Recent additions include ground coconut shells, silver, gold, platinum, and diamonds. Different means, same goal. Again, each brand's filtration approach is based on its preference and specifications. Is one material or method better than another? Arguably not, as long as the producer is satisfied that the method is delivering the desired outcome.

Maturation and Mingling

Vodka is for the most part an unaged spirit. Only rarely does it spend any appreciable amount of time maturing or "resting" between the filtration and bottling processes. Some producers feel that the rigors of distillation are tempered by resting, which allows the water diluent to integrate into or mingle with the spirit. Unlike for dark spirits, resting for vodka does not occur in a wood container but in a stainless steel or another vessel that is incapable of imparting flavor.

There are a few points in the vodka production process where mingling may occur: (1) when mixing several runs or batches in pursuit of overall consistency, and (2) during the resting period. As noted, the goal of mingling is to give the added water the opportunity to harmonize with the distillate to improve the final product.