Goose Island Clybourn will release the final addition to its 25th Anniversary Bottle Series this Saturday, a sour, barrel-aged wheat beer called Brettanomite.
At $20 per 750 Milliliter bottle, the limited-edition wax-sealed and hand-bottled Brettanomite is more than just a bottle of beer — it’s a connoisseur creation, the product of careful engineering and experimentation. Goose Island Clybourn master brewer Nick Barron shared the story behind the brew:
Brettanomite began with a brainstorm. The four brewers at Goose Island’s Clybourn and Wrigleyville brewpubs “put our heads together to get a sense of where we were trying to go with the flavor of the beer, and kicked around different ideas,” Barron said.
The brewers also considered their audience. Sour beers like Brettanomite are polarizing, because, “traditionally speaking, your beer is intended to be a clean, crisp product. Traditional brewing processes try to absolutely discourage any sourness going into the beer.”
In cultivating a sour beer, however, Barron also tapped into a market of dedicated sour beer devotees. “It’s definitely a smaller group of people who are really into it, but when they’re really into it, they are fanatical about these type of beers. They typically do really well for that small a market,” Barron explained.
Then began the brewing process [see related content], culminating in the addition of yeast, Brettanomite’s most notable ingredient and its namesake. The brew is named after the two types of wild yeast that it comprises: Brettanomyces lambicus and Brettanomyces bruxellensis.
These two are known as “wild” yeast strains and hearken back to a centuries-old process practiced in central Belgium, spontaneous fermentation. The yeast grew wild on the skins of orchard fruits, and brewers would place containers of beer on the roofs of buildings in order to capture the yeast and begin the fermentation process.
“The winds blowing back and forth across the cherry orchards or the fruit orchards would actually blow yeast into the beer, so it would take off on its fermentation more or less spontaneously, very naturally,” Barron said.
Replicating the spontaneous fermentation process in Chicago is next to impossible, Barron said. “It’s very rare to come across a situation where you can actually do that type of spontaneous fermentation because all the stars have to be aligned. You have to be situated where the local ambient air is laden with the appropriate amount of yeast strains, just floating around in the wind.”
Instead, Goose Island Clybourn used the Goose Island Beer Company’s laboratory to engineer specific yeast strains for the beer. At the lab, scientists cultivated the yeast strains from a single cell to prevent cross contamination.
Barron then added the yeast to the unfermented Brettanomite before letting the mixture ferment in oak barrels. The barrels allowed the yeast come in contact with oxygen, ferment the beer, and “kick out a lot of organic acids, which acidifies the beer and gives it its unique flavors,” Barron said.
Once the yeast was in the barrels, the experimentation process began. “We don’t 100 percent know when the beer is going to be ready to pull out of the barrels. We have a rough time that we’re looking for, but at the same time you taste it several times over the months or even years that it’s there in the barrel to get an accurate sense of how it’s performing. We just try to see where it goes and follow where it takes us,” Barron said.
Brettanomite spent 13 months aging in the barrels before Barron determined it was ready for bottling — and buying — this week.
Three hundred bottles of Brettanomite will be available at Goose Island Clybourn beginning at 10 a.m. Saturday.