GOLDEN, Colo. — In a corner of the Coors empire, in what used to be a storage room for bags of malt, a group of brewers is experimenting with beer that never will be advertised during the Super Bowl.
Look closely at an oak barrel, and you’ll notice a sticker from the Belgian brewer Cantillon, a source of inspiration. The humming sound is from exhaust fans partly responsible for bringing Coors Light to the masses.
The beers slowly aging in the barrels are funky second cousins to the Silver Bullet — part of a wave of mouth-puckering yet drinkable sour beers capturing the interest of craft brewers and drinkers.
Consumers are about to get their first taste of the efforts at AC Golden, the MillerCoors craft beer incubator best known for Colorado Native lager.
Limited quantities of three sours — an apricot, cherry and peach — will be available in 750-ml bottles exclusively at Mile High Wine and Spirits in Lakewood later this month for about $21.99 each.
“The biggest reason we are doing this is we like to drink these,” said AC Golden brewer Troy Casey, 28, part of a younger generation of Colorado brewers.
The brewery acquired its first barrels three years ago and kept its work quiet — one reason it became known as the Hidden Barrel Project.
“... Probably the biggest reason was that we didn’t know if we were going to make a drinkable product,” said Casey.
Sours encompass a family of beers, fermented with unpredictable wild yeast and bacteria, that are expensive and time-consuming to brew.
The Boulder-based Brewers Association recognizes 13 variations of American-style sours. A whiff of a sour beer inspires descriptions such as barnyard, funky, horsey — and, yes, baby vomit.
And this is supposed taste good? Yes, that is the point, Casey said: to create enjoyable sours.
To brew the Apricot, AC Golden starts by fermenting a “base beer” in stainless steel tanks — a low-alcohol neutral beer Casey likens to a blank canvas. Next, the beer is moved into the barrels.
The brewers then add the co-conspirators: multiple strains of the wild yeast brettanoymces and various Lactobacillus, an acidifying bacteria that produces the sour character.
After eight to 10 months in the oak, brewers shovel in 120 pounds of Palisade apricots per oak barrel, displacing a lot of beer.
About three months later, what emerges is a super-dry, slightly hazy, balanced not overwhelmingly fruity beer that is only 5.5 percent alcohol by volume, very drinkable for being so complex.