Most breweries seem to have had a crack at aging beers in some type of whiskey barrel, it has become one of the go-to techniques when building a portfolio of craft beer. The idea was initially popularised by those canny chaps at Goose Island after it released its Bourbon County Brand stout over 20 years ago and has been creeping into many other brewery offerings with greater frequency ever since, and consumers demand increased flavor experimentation.
However, while the payoff is (literally) very sweet, the process is not without it’s challenges. American whiskey barrels are tough to track down and are often in pretty bad shape upon receipt, so they can be quite expensive and tedious to use. They’re built to only be used once, so they’re not as nicely built as wine barrels, with a lot more inconsistency in volume, rougher staves and the oak or char you pick up from one to the next varies a lot.
[Beer geek warning!!] However, the final product is well worth the effort. Beers aged in the process gain a new, smoother texture and a slightly oilier mouthfeel, as well as delicate vanilla, subtle oak wood and coconut, and burnt marshmallow notes — depending on what types of whiskey barrels are used. Then there’s impressions you get from the barrel that you can’t taste, a texture like a silkiness. You’re changing esters and alcohols into new components so things are combining and mingling and changing over the eight or nine weeks, or months, or years in the barrel. You’re getting a lot of micro-oxygenation over time in a process of slow aging you can’t get in a fermenter or a keg.