Introducing the wild side of beer--far away from the standard ales and lagers we know and love--making sense of the funk can be a tricky business. But have no fear, this article will take you on a journey, introducing you to Saccharomyces Cerevisiae and S. Uvarum and the team of bacteria that make sour beers what they are--tangy, tart and truly wild!
If you’re a fan of craft beer, chances are you’ve savoured the taste of tart, sour beer or perhaps even taken a sip of a gueuze. Sour beers are fermented from microorganisms other than just yeast, giving it a truly unique, muted flavour. But where does that tantalizing funk come from? Let’s take a look at the unusual team of microorganisms that contribute to the creation of a sour beer.
Joining our trusted actors Saccharomyces Cerevisiae and S. Uvarum in the world of sour beers are a team of misfits that would make the Bad News Bears proud. Let us meet the bacteria swimming in your beer.
Though our friends Lactobacillus and Pediococcus don’t often get the same level of media attention that you might find for Saccharomyces, these two make up much of the production of sour beer. Indeed, the lactic acid that gives off the sour taste is primarily created by Lactobacillus.
Often referred to as a “Lacto”, this bacteria is best suited for a low-gravity, low-alcohol wort. Depending on the beer style and the brewer’s intention, Lacto can contribute a yogurt-like aroma and taste and is essential in the production of Berliner Weisse and other sour-style beer. This bacteria is usually added in addition to, or after, an initial yeast strain.
This bacteria produces a much more tart flavour than its friend Lacto and typically results in a beer with a thicker body and complex mouthfeel. Where Lactobacillus is sometimes used as the sole source of fermentation, Pedio is best used to supplement a sour beer and can be utilized both in the boil and during fermentation for additional complexity.
You may be familiar with Acetic Acid from the wonderful aroma of vinegar, and the Acetobacter bacteria is the source of that sharp smell. Though this bacteria is usually an unwelcome guest in most beer styles, it is essential in traditional lambic beers, contributing to the sour and vinegar-like aroma. Left unchecked, these bacteria can devour your beer by producing far too much acetic acid, so they’re usually treated with caution.
Whether you love them or you hate them, it’s fair to say that the microorganisms discussed above are indispensable in the production of sour beer. By working in harmony with our good friends Saccharomyces and S. Uvarum, this motley crew of misfit bacteria help to create the unique, tart flavours that make sour beer such a beloved delight. Next time you’re enjoying a sour beer, show some gratitude to the bacteria that made it possible.