The Barrel

I’ve made no illusions about the fact that I am a massive brewing nerd. The blending of science and art to create something as old as civilization yet entirely brand new. You can’t know where you’re headed unless you take the time to look back and figure out how you got to this point. This idea becomes tangible when learning how to work and brew with barrels. 

Barrels are old, old things and marvelous examples of engineering and craft. Just as pallets are essential to modern day commerce, barrels and the coopers that made them were indispensable to trade throughout history. They were used to store and transport all manner of goods from produce to gunpowder. The handmade curves and bulge of the barrel allow it to be handled by a single person. A single person can tip a full barrel over, roll it, turn it on a dime, and stand it back up surprisingly easily.

For obvious reasons, the most difficult barrels to make were watertight barrels. The staves and heads that make up the sides and ends of the barrels must be sawn, shaved, and shaped masterfully so as to not leak whatsoever, because that’s just a waste of good beer. A good barrel does not require any sort of sealant to be watertight. The wood (if put together well) will be naturally watertight and become even more so when filled. This was all done entirely by hand well before the industrial revolution and modern machining.

The flavor most people associate with barrel aging is simply the flavor of the wood that beer or liquor was stored in, typically charred white oak. The inside of each barrel is toasted to a specific temperature for a specific time to achieve the desired flavor. Light toast will give vanilla and leave far more oaky, tannic flavors. A moderate toast will give stronger vanilla, toffee, and even some spice. Dark toast can give coffee, chocolate, and some smoky flavors. Back in the pre-industrial barrel making heyday, some coopers lined their barrels with pitch to both enhance the watertightness and prevent the flavors of the wood from leeching into the beer.

The world of spirits and wine are pretty much all that’s left of the once massive barrel-making business. In the modern day, barrels and the coopers that make them are not as necessary to global commerce as they used to be, but you can’t make bourbon without a fresh barrel - and I mean that in the legal sense! Bourbon legally must be aged in a fresh white oak barrel, after which it can be used for anything like another type of whiskey, gin, wine, or even beer! There will always be bourbon barrels for sale and some distillers even give them away, because at some point they’re just taking up space. So we crafty brewers talked to our friends in the distilling world and decided to take a few bourbon barrels off their hands and give barrel aging a try. This is why you will often see bourbon barrel aged beers and not gin or cab sauv barrels. 

The way barrel aging works for beers is fairly simple. The beer ought to be fairly high ABV (generally above 7%, but the higher the better) as standard strength beers contain a lot of nutrients that bacteria love (compared to wine and spirits) and they do not have enough alcohol to ward off spoilage bacteria. The beer also ought to be a style that can withstand some oxygen and aging: stouts, barleywines, or very sharp sours. IPAs and anything with a lot of hops do not handle aging gracefully and any sort of bitterness just doesn’t taste good with tannic oaky flavors.

Barrel aging will impart the characteristics of the wood it is made of as well as whatever previously inhabited the barrel like a wine, spirit, or other beer. Most any tight grained hardwood will work for a barrel, including fruit wood. Barrel aging a beer requires the brewer to be less rigid in their work and instead be more artistic and listen to what the beer is telling you. There is no set timeline to be followed - there are far too many variables between type of wood, region it was grown, time it was harvested, how many times has the barrel been used before, etc. The beer is ready when it tastes ready and no two batches will be the same. It all comes down to patience and a discerning palate.