One of my favorite things to do in the brewery is to age beer on wood.
Fermentation of beer in wood vessels was done for centuries, but the inside of the barrel was covered in pitch for sanitation reasons, so the beer never actually contacted the wood. Today, I'm talking about beer and wood contact. The beer actually makes its way into the wood as it ages, allowing flavors and aromas to develop over time.
In the course of my career, I have aged beer in bourbon barrels, whiskey barrels, scotch barrels, cognac barrels, port barrels, sherry casks, schnapps barrels, white wine barrels, red wine barrels, tequila barrels and liquor barrels. Allowing beer to age on wood creates an almost miraculous bounty of flavors and aromas. Bourbon barrels are especially fun to use, and we brewers are very fortunate that the Kentucky bourbon standards allow a barrel to be used only one time to produce bourbon. So, that means the bourbon barrels are not too hard to source.
Choosing the beer style for barrel aging is just as important as the choice of the vessel. Some brewers might say any beer can be barrel aged. They would not really be wrong, but I personally have some general preferences including higher alcohol content choices such as Belgian dubbels, wheat wines and other strong wheat-based beers and strong scotch ales. Less strong styles that I like to age in wood are malty beers, like stout and porters, fruit beers and bock styles.
In some cases, such as the Lambic beers brewed in Belgium, fruit is added after a time to trigger a re-fermentation in the barrel itself.
I also enjoy hybrid beers where the real art of barrel aging beers comes in: the blending process. Nearly all of the beers we age in barrels go through a blending and flavor-maturing process. For example, if we have six bourbon barrels filled with Imperial stout, each barrel will taste different due to the unique characteristics of the barrel it sits in, and we'll do a batch blending when the beer is ready. Usually the first three months or so we leave the barrels undisturbed. After that—and in conjunction with our release plans—we'll sample each barrel about once a month. This is done by drilling a small hole in the front of the barrel and allowing a sample to fill our tasting glass, then sealing the hole with a stainless steel nail.
When the beer is deemed ready, we transfer the barrels into kegs, or if some barrels are considered to be close enough to the goal, we may blend barrels from the same batch into a different vessel on site. We then draw individual samples and conduct in-depth sensory trials on beers, to then decide how much of each keg should be blended with another keg, and so on. It is a long but very fulfilling and fun process.
Often, we blend different styles of beers from different wood barrels. For instance, a few years ago, we made a very well-received beer that was 50 percent cherry beer aged for one year in a third-generation bourbon barrel and 50 percent Belgian Grand Cru aged one year in a red wine pinot noir barrel. A Cherry Grand Cru — that was truly delicious.
I know of a brewery in California that blends up to 12 different styles of beers from different barrels for their anniversary release each year. They bring in local winemakers as well as other tasting experts to perform the sensory work.
The world of barrel-aged beers is fun and extremely enriching for the beer lover.
I'll close with some nice examples of barrel-aged beers available at Duluth-area shops.
• Barrel-Aged Double Shot Black from Bent Paddle
• Barrel-Aged Darkness from Surly
• Terreux Quadrupel from The Bruery
• Melange, also from The Bruery
• Barrel-Aged Stout from Central Waters
• Dissident from Deschutes
• The full barrel-aged lineup from Harviestoun Brewery in the U.K.
• La Folie from New Belgium
• Any barrel-aged beer from Cascade Brewery Barrel House
• Vintage from Rodenbach Brewery
• Vanilla Bean Stout from Avery Brewing
Dave Hoops lives in Duluth, Minn., and is a veteran brewer and beer judge. Contact him at firstname.lastname@example.org.