From the Bottom of the Barrel: 5 Ways the Barrel Affects Your Batch

Proof 33

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Long before the inside of a barrel sees any spirit, it undergoes a conditioning process that could literally be described as a walk through hell.

With a seasoning process that includes multiple exposures to heat and flames, everything the barrel goes through before it gets to your warehouse is in preparation for the months or years it will spend as the vessel for your favorite hand-crafted spirits. The barrel is really the final tool that allows diverse flavors to develop in every small distillery.

Differences in barrel characteristics impart unique qualities to a spirit during the aging process. Filters do the heavy lifting to give you a true, pure product, while aging gives the alcohol that smooth mouth feel and imparts some color, flavor (like vanillin from wood tannins), and aroma.

Regulations on spirit distillation and production in the U.S. mandate that whiskey and bourbon be aged in charred new oak barrels, and can only be used once. This rule, a remnant of the Depression era, remains in place today mostly because it contributes to ensuring a consistent quality aging process. After the first use, producers of other liquids and spirits, like Scotch, tend to purchase these barrels that retain some of that sweet, vanilla-like flavor. Even coffee and beer brewers are clamoring for used barrels.

Like all parts of craft production, there is a tangible passion for barrel-making that involves skills passed down for centuries. We spoke with John Cox of Quercus Cooperage in High Falls, NY to get to the bottom of his craft barrels.

1. Know Your Wood

The benefits of American white oak (Quercus alba) – its tight grain that doesn’t leak, its clean composition that won’t impart much resin to your product, and the aromatic quality it imparts to your spirit – make it the most commonly used wood for aging spirit like whiskey.

The region your wood comes from is also said to affect the colors, flavors, and aromas the wood imparts to your product. Region has become a big selling-point for distilleries on the rise, like the makers of New York-based Empire Rye. Cox notes that Quercus Cooperage’s New York wood has a distinct honey-vanilla flavor.

2. Size Matters

New craft distillers will typically start with smaller barrels to enable faster maturation in order to bring product to market quicker. Established distilleries use larger barrels because they can afford to age product for months or years at a time, which arguably allows for the development of more complex flavors. Larger barrels are typically machine-made and seen as disposable commodities. For the craft distiller, the typical barrel is usually no larger than 30 gallons and the wood and craftsmanship is of utmost importance.

3. The Reason for Seasoning

The drying and conditioning processes develop lipids, the oils found in the wood. The increase in lipids during the seasoning process enables the wood to produce enzymes which in turn allow fungi and flora to colonize the wood. This colonization softens the bitter flavors of raw wood and adds additional aromatic characteristics, including vanilla, clove, and coconut, which will be absorbed by the product as it interacts with the wood during the aging process. Climate plays an important role and can vary from year to year.

4. Time to Get Toasted

Fire- or heat-toasting barrel wood develops sugars in the wood by burning the cellulose of the grain. The amount of toast you want on your barrel is determined by the level of a specific character you wish to impart on your spirit. There are five main levels of toasting: light, medium, medium plus, heavy, and toasted heads.

Light toasting – using less heat – preserves more tannins, or structure and lactones from the wood in its natural state. This will impart woody and coconut flavors (the coconut character is typically associated with bourbon). A heavier toast results in spicy and smoky notes. Vanilla flavors are unique to medium toasts. Medium Plus is the most common toast level for barrels and is also the most complex, as low toast levels have yet to dissipate, and high toast level tones are starting to develop. A deeper toast will result in caramel and butterscotch tones.

5. From Char to the Bar

More than just a flavor-enhancer, aging in charred barrels is also the slow way to filter impurities: the char in the barrel acts as charcoal, filtering the liquid and leaving a smoother product. There are five levels of charring a barrel, which involve exposing the inside of the barrel for a specific amount of time to a 1300-degree fire. Cox uses levels on a scale from 30 to 50 seconds. The result will be “alligatored” wood texture at level four, to flaking wood at level five. Some barrels depending on their application will endure a double-char. Cox controls the fire inside the barrel with a handful of sawdust and compressed air, leaving the barrel smoking and crackling, but never burning. “It doesn’t smell like a house on fire,” Cox says, “it smells like a bakery.”

The pleasure a cooper derives from sticking his head into a newly-charred barrel must be like the satisfaction of a distiller taking the first whiff of the golden juice just tapped from a barrel that’s been aging for months. What did you get? Is it floral, fruity, spicy, sweet?

Which brings us to the best part: the taste test.

Need input on what kind of barrels, barrel equipment, and barrel alternatives are best for your craft operation? Get in touch with our inventory experts!

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