Trending now are sour and funky beers, many of which are created by mixed fermentations of yeast and bacteria to replicate flavors associated with traditional farmhouse ales. To create these complex, nuanced, and often unexpected beers, craft brewers are fermenting beers with Brettanomyces and bacteria such as Lactobacillus and Pediococcus, among other microbes. Some are are even fermenting their beers with naturally occurring airborne yeasts and bacteria that they capture from the air.
Brett, Lacto, Pedio
The most common yeast-bacteria cocktail used in sour and funky beer-making is the Brettanomyces, Lactobacillus, and Pediococcus trifecta. Brettanomyces, or Brett, is a yeast strain that ferments more slowly than standard Saccharomyces. Brett has many different strains that yield a cornucopia of flavors and aromas, most notably barnyard funk and horse blanket. Brett creates earthy, fruit, and floral characters in beers as well. Lactobacillus and Pediococcus are bacteria that consume sugar and leave lactic acid in its place, creating tart and acidic qualities in beer.
“We sour our beers with intentional inoculation coupled with unintended organic fermentation that comes along with reused barrels,” says Douglas Dayhoff, the president at Upland Brewing Company in Bloomington, Indiana. “We inoculate our wood-aged sours with the combination of classic microbes—Brett, Lacto, Pedio. This helps us gain a certain amount of control before embedded microbes in the foeders and barrels further develop the beer’s character over time. We’ve seen the embedded microbes in that wood actually help accelerate and create better fermentations.”