Patience is a virtue. To Cory King of Side Project Brewing, it's also an art. Every beer at Side Project is barrel-aged, meaning each batch has to sit for months, even years, before he deems it perfect. It may sound like a chore, but King sees it as a labor of love.

"You go into a brewery and it’s all this shiny stainless steel that [feels] more like a factory job," King says. "I feel as though the barrel-aging side is more of the art of it, to where you’re blending and tasting, and each barrel is its own micro-environment.”

Beers that age inside specified barrels take on characteristics from the barrel's past inhabitant, giving the brews qualities they couldn't otherwise obtain. Bourbon and wine barrel-aged beers tend to be most popular, but trends have since shifted to more atypical spirit barrels, like gin and cognac. Goose Island's "Bourbon County Brand Stout" is often credited with reviving the practice in 1992.

Now, barrel-aged beers have skyrocketed in popularity once again, with breweries across the world seeing what strange and hybrid concoctions they can make. King says experimentation is the name of the game now because the consumer demands it.

“The American craft beer movement has really revolved around intensity of flavors," he says. "The craft drinker is always out to find bigger, better, bolder."

A Successful Slumber

Quite a bit goes into successfully barrel-aging a beer. Since beers are often left in a cellar to age, time is everything. That desirably bold and hybrid beer can't reach its peak in a day or week — it takes months. Alex Leonard, cellarman for 4 Hands Brewing Co., says the best thing to do is patiently check progress.

“About every nine weeks, we’ll do what’s called ‘pulling nails,’ which is literally pulling stainless steel nails out of all the barrels," Leonard says. "We’ll pull them out and capture a sample.”

Leonard is in charge of more than 200 barrels in the brewery's upstairs area as part of a recent expansion. 4 Hands launched this new barrel-aging program six months ago, which saw the addition of 7000 square feet dedicated to barrel-aging.

But 4 Hands brewery manager Martin Toft says you can't sample too much, otherwise the beer's sanitation and aeration elements are ruined. Not to mention the beer itself is depleted. 

“It’s really easy to sample these barrels too much and put too much thought into it," Toft says. "But let the barrel do its thing, let them produce all those flavors, and make sure you monitor its progress.”

The type of barrel being used plays as big of a role as the style of beer aging — tequila barrel-aged beers can be ready in as quick as a few weeks, while sour beers can take over two years. Higher alcohol content beers also tend to lend themselves best to aging. With so many possible combinations and additions, countless breweries are looking to barrel-age the next big hit.

“It’s something that isn’t as replicable across breweries," Leonard says. "Most breweries can make a double IPA with a particular hop. Barrel-aging is not only a chance to make yourself stand out as more of an individual within style guidelines, but also the risks that are taken with barrel-aging and the ways those beers can mature.” 

Those risks come with batches falling flat, or not meeting expectation. Sometimes, the cards aren't in a brewer's favor and a barrel is bad from the start. King says Side Project dumped four oak barrels before filling them last year, out of about 60 total in his possession. But in the brewery's three years in business, King says he has never had to get rid of an awful batch because of "blending."

King says blending is one of the most important aspects to barrel-aging beer. This means combining different batches of barrel-aged beer to reach certain flavor profiles and complexity. It's common for a brewery to blend a lackluster brew with another batch instead of just throwing it out.

“You can use that as a piece of the puzzle for a better beer,” King says.

Blending can make up lost ground from having a bad barrel as well. King says he'll even brew with blending in mind to reach a desired end product, making it such a valuable tool to the barrel-aging process. Side Project's "Pulling Nails" is a blend of four different barrel-aged batches.

Supply and Demand

King says the future of barrel-aging is hazy. The trend has taken off so much in the past few years that barrels are getting harder and harder to obtain. 

“The bourbon and whiskey barrels are getting almost impossible to source," King says. "Now we have all this demand locally and in the United States, and these guys just don’t have them.”

This shortage, he says, is because everyone wants in on the trend — especially macro-breweries. Breweries like Side Project, then, are left to go through brokers, who will normally side with the bigger fish.

"Oh, well Goose Island orders four truckloads from me, a thousand barrels at a time, and you want 12?," King says.

While King says that wine barrels will most likely stay steady in production, bourbon and whiskey barrels, which are considered the most popular barrels for aging, are now the most scarce. This has led many breweries to reuse their barrels for multiple aging cycles, which King says leads to sub-par batches of beer.

Reusing barrels strips the wood of its respective spirit and flavors, eventually amounting to just a vessel. King says it also waters down the art of the process, as a beer aged in a bourbon barrel on its fifth aging cycle won't carry many of the qualities it claims to. He recommends a barrel only be used two or three times max.

King says the next five years will be definitive for the future of barrel-aging beer. Barrels will come and go, styles will be exhausted and risky experimentation will reach peak levels. The coming years will separate who's doing it for the art, and who's doing it to follow suit.

“I’m not putting in the oak out of the novelty of it," King says. "I’m putting it in because I want to get something from that oak. Unfortunately to some, barrel-aging is a fad. To others, it’s really what they’re trying to do."


Hungry for more Midwest food-scene news? Follow us on:

Click here to subscribe and each month you'll receive a delicious serving of Feast delivered directly to your home, hot off the presses!

Subscribe to our weekly enewsletter here!

Subscribe to Breaking News

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.