An up-and-coming trend has hit the Kansas City craft brewing scene — sour beer.
Characterized by a distinctly tart flavor, sour beer is full of bacteria and microorganisms, has a higher level of carbon dioxide, and is reminiscent in taste and smell of underripe fruits and overripe cheeses. Sound appealing? For some, it's a delicious refreshment. For others, it is unpalatable.
"It’s going to give a lot more pop, a lot more dancing on the tongue," said Brian Buckingham, head brewer at Cinder Block Brewery.
"There’s this reaction that occurs in your mouth. It helps me grow sideburns," Jeremy Danner, of Boulevard Brewing Company laughed.
Both Cinder Block and Boulevard, two local breweries, are embracing the movement.
"I would say it’s definitely catching on in Kansas City," Danner said. "It’s been more of a trend on the coasts for quite some time. As people’s beer palates evolve and as education gets greater in Kansas City, we have more breweries opening and doing cool things."
Though this is a relatively new trend in Kansas City, it turns out most of the first beers ever brewed were sour, due to a general lack of understanding of sanitation and fermentation. According to Danner, each family of early nomadic brewers had a "magic stick" that they would put into the wort, which is the liquid fermented to make beer. They believed this induced fermentation, but in reality, the stick introduced a yeast that turned the beer sour.
Specific strains of bacteria (Lactobacillus and Pediococcus) and yeast (Brettanomyces) are intentionally introduced into the brew for sour beer. This combination and the aging process distinguish sour beer from your average craft malt beer.
Some breweries, like Boulevard and Cinder Block, age their sour beer in old wine or whiskey barrels, where they inoculate the brew with the bacteria and sometimes fruit, like blackberries or strawberries for extra acidity. But actual fruit is sometimes not responsible for the fruity flavor.
"[Lovechild No. 5] itself is very fruity, but there's no fruit in the beer, which I think is a cool expression of the barrel character and that wild fermentation that occurs," Danner said.
That particular Boulevard sour, the fifth iteration of its kind, is a blend of several ages of a Flanders red, a Belgium style ale, that they brewed for several years in separate various vessels, including whiskey and wine barrels and a "fooder," before blending parts of each back together to showcase fruity notes.
In Cinder Block's Freak of Nature, the brewers introduced peach and apricot puree to the brew and aged it for 11 months in chardonnay and merlot barrels.
"We’ve been taught that bacteria is bad — we use antibacterial soap, antibacterial hand sanitizer — but bacteria is good for you," Danner said. "It’s in your body, it helps you digest food. Basically these bacteria we’re adding to the beer are doing the same thing that the bacteria in your body does; they’re consuming sugars and starches and creating lactic acid that provides that pleasant sourness."
The bacteria used in sour beers are resistant to most cleaning techniques, so the process requires entirely separate equipment — pumps, hoses, gaskets, barrels, tanks — and a pretty extensive cleanup routine to avoid contaminating the other beer.
Boulevard actually rented caves just outside of town designated specifically for sour brewing, and even there they have walls between sour barrels and clean barrels, where the beer is transferred after aging.
Time remains a great hurdle for breweries wanting to make sour beer.
"It's tough to say to a brewery owner, the brew that we're brewing today won't be ready for six years," Danner said.
But that's not stopping the trend. In addition to Boulevard and Cinder Block, a few other local breweries like Torn Label Brewing Company and McCoy's are experimenting with sour beers. Crane Brewing, set to open in Raytown this year, plans to focus on sour beers.