By now as a craft beverage enthusiast, you have almost certainly seen or heard of barrel-aged brews, you probably have even tried at least a couple of the ones currently on the market. Barrel-aging Lagers, Ales, and everything in-between can yield a very unique finished product. The goal of the barrel aging is to impart the flavors of the wood of choice upon the brew of choice. “Today’s craft brewers are using wood (mostly oak) to influence flavor and aromatics. Beer may be aged in wooden barrels (new or previously used to age wine or spirits), or chips, spirals and cubes may be added to the conditioning tanks that normally house beer. A variety of types of wood are used including oak, apple, alder, hickory and more. The interior of most barrels is charred or toasted to further enhance the flavor of the wood.” via CraftBeer.com
One of the most commonly barrel-aged varieties of beer would be your traditional lambic sours. These purposefully contaminated beer is often fermented in used barrels for both the wood taste it will leave as well as the bacterial content of the barrel. Some stouts, especially Russian Imperial Stouts are often aged in old bourbon barrels to impart both the taste of the wood and the taste of the bourbon into the craft beer.
Barrels You Say?
For beers that aren’t supposed to be sour’s you often can only get one good use out of a barrel before the main flavor characteristics are gone. After using the barrel for a beer such as a wood flavored stout the barrel may be saved and allowed to sit with bacteria in order to become a barrel used for fermenting sour beers.
Once a barrel has been used for sour beers it’s near impossible to return the barrel to non-sour condition again. Some brewers who want a bunch of smaller batches of sour beer at a time will do a big barrel batch and then just pull our small 5-gallon batches at a time and do additions to the sours as they feel fit. In the process, new beer is added to the barrel to prevent oxidization and the sour bacteria will continue to live on and on replicating on the new beer regularly added.
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