April is a high-pollen month, particularly in the northwestern part of Colorado Springs, where the winds blow hard around Trinity Brewing. It's the kind of month when you can find all kinds of things floating in the air, things that make people sneeze, swell their eyes shut -- and maybe, just maybe, help to produce a very unusual beer.
Next Tuesday, Trinity Brewing founder Jason Yester plans to become the first commercial Colorado brewer to ferment a beer using naturally-occurring bacteria and yeast.
Brewers in other countries have used the technique, known as spontaneous fermentation, for generations, but it's particularly associated with Belgium, where breweries like Cantillion use open vessels called koelschips -- or coolships -- to capture the yeast.
Brewing in this style typically results in "wild" beers that have sour and funky flavors that wouldn't be produced -- or allowed -- in traditionally fermented ales.
"That is the whole point of view on that beer, allowing the indigenous microbes to blow into the open wort as the source of fermentation," Yester says.
Trinity had its coolship custom-built with castors so that the vessel can be rolled outside; in most breweries that use spontaneous fermentation, the coolship sits in a permanent location in a room that is left partially open to the outside air.
The plan is to brew a batch of lambic-style beer, pump it into the coolship and then let it sit overnight in an exterior fermentation room with the doors open.
From there, it will be poured into chardonnay barrels, where it will age for -- take a breath -- three years. Yester will brew a second batch of the beer in April 2015 and third in April 2016, and then blend them all together before releasing it in April 2017.
"By blending them all, the resulting beer is extremely complex," he says, adding that if this project is successful, it will result in the first coolship-produced beer in the state.
It's a high-risk, high-reward experiment, but one that is worth doing, Yester adds: "I'm not quite sure what to expect out of the result, but we've always pushed the boundaries of beer and the use of the coolship will take beer to it's outer most limits."
The only other Colorado brewery that includes a coolship is Crooked Stave, but owner Chad Yakobson hasn't begun using it yet -- and he has said previously that he doesn't necessarily plan to make spontaneously-fermented beers with the equipment.
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