FOUNDATIONS of CRAFT DISTILLING WRITTEN BY GABE TOTH
4: Aging/Bottling
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s the American craft spirits world grows, new and would-be distillers do not always have access to the best information on the fundamentals of distilling. What worked for grandpa in the woods, or a friend’s methods on their garage still, doesn’t always translate into making the best possible product for a commercial operation. To that end, we hope to provide some basic, foundational distilling knowledge for new craft distillers and those who have not been formally trained in a series of articles that cover the key foundational components of distilling at a craft level. READ FOUNDATIONS While the princi- OF CRAFT DISTILLING 1: MASHING ples laid out in this and previous articles are not always hard and fast rules, there are often good reasons that they have READ FOUNDATIONS become guiding OF CRAFT DISTILLING principles. Rules can 2: FERMENTATION be broken, but one should learn the rules in order to know best how to break them. As much as possible, we will attempt to READ FOUNDATIONS explain the reasons OF CRAFT DISTILLING 3: DISTILLATION for these principles or best practices, but given the space constraints of a magazine, this will not always be possible. This article, Aging/Bottling, continues and builds on the content from the Mashing, Fermentation, and Distilling articles in previous issues of Artisan Spirit. W W W . ARTISANSPIRITMAG . C O M
Aging Barrel-aging is a cornerstone of many types of spirits, whiskey in particular. Estimates vary on just how much of a final barrel-aged spirit’s character is contributed by oak and the aging/maturation process (Is it 50 percent? 75 percent?) but it’s inarguably a significant factor. Spirits undergo a variety of chemical transformations in the barrel; it’s a tremendously complex process that’s not entirely understood. However, there are three primary avenues of change that occur in the barrel: evaporation, extraction, and transformation. Evaporation is the result of barrel contents transiting slowly through the porous oak. A certain amount of loss is to be expected and
is even desirable, as it results in the removal of undesired flavors and a relative concentration of desired flavors. Evaporation in barrel maturation is not isolated to the water and ethanol that are the primary components in a spirit. A variety of less desirable compounds, or compounds that can be desirable in very low quantities, will pass through the microporous wood structure and evaporate. These include acetaldehyde, dimethyl sulfide, and a variety of the lightest alcohols that occur in heads, which can bleed into the hearts depending on other factors in distillation. In addition, as the angel’s share increases in the barrel, the less volatile compounds will actually increase in concentration, potentially improving the flavor of the spirit. 77