Sour beers have been gaining immense popularity and intrigue here in the US over the last few years, with interpretations of classic Belgian and French styles popping up at breweries everywhere. New style fusions and challenging concepts are emerging plentifully as well. Sours and brett beers are certainly on the “hot list,” sought out by seasoned consumers as well as buzzword-toting trend followers. So really, what is all the fuss about?
First let’s get friendly: brettanomyces or brett, for short, is a type of wild yeast commonly found in nature, frequently lounging on the outside of fruits such as grapes. It’s an acidogenic organism that enjoys eating glucose and other sugars, producing acetic acid in return. Not all sour beers utilize brettanomyces cultures, and many sour beers showcase multiple yeasts and bacteria including but not limited to: lactobacillus, pediococcus and other possibly unknown or unnamed wild yeasts. Brettanomyces acts and interacts differently from typical beer yeast and produces specific flavors that some enjoy and some detest. While it is possible to use brettanomyces by itself in a primary fermentation, it’s more often added after the first round of fermentation is complete. This primary fermentation could be via typical beer yeast (saccharomyces, the workhorse!) or in concert with saccharomyces. Brett is a particularly slow worker with certain nutritional needs and demands on environmental factors. Its flavors in aged beers can take months or years to be ready to drink. Of course, it’s the brewer and/or blender and finally the consumer who decides what “ready” is. How to tell? A difficult question to answer, but Wyeast Laboratories says that 1-2 years is a common timeline for thorough brettanomyces development. The process is somewhat comparable to winemaking which requires a diligent tasting regime, patience in aging and a deft hand for blending.
It’s important to consider the risk set forth by undertaking a brettanomyces beer. Brett is extremely tenacious and can be nearly impossible to remove from brewing equipment, which is why breweries that make sour beers often have entirely different sets of equipment, systems in different buildings, or at the very least keep their aging area substantially segregated from non-wild beers. Unintentional infection by brettanomyces or other wild yeasts and bacteria can mean a huge loss of product and surrender of equipment. Thus, a high level of surveillance and caution is necessary in commercial mixed-culture breweries. Kettle sours like Berliner Weisses and Goses are faster, safer options that many American breweries are choosing to experiment with. While brettanomyces is sometimes used in those styles, it’s not a necessary element.
Flavors introduced by brettanomyces vary, but common descriptors include spicy, funky, barnyard-like, cheesey, band-aid-like and horse blankety. Yes, many of these terms sound unpalatable, but the right amount and combination is striking, complex and often complementary to the malt profile, especially when fruits are also added. And certainly we can’t forget the eponymous sour flavor, which also ranges from lightly tart to pungently acidic. Ultimately, you can’t ever be sure of what you’re going to be tasting in a mixed-culture beer, and this makes sampling and home cellaring of bottles exciting (and sometimes a bit of a crapshoot).
Luckily there are a number of American breweries that are devoting all or most of their production to brettanomyces beers, so choices for drinking are many. But to begin, I’d suggest trying a classic Belgian brew, Orval Trappist Ale. Orval is dry hopped with continental landrace hops and aged very briefly with brett. Its light-handed maturation period provides a restrained yet very present brettanomyces character. For bold American creations, try Seizoen Bretta from Logsdon Farmhouse Ales in Hood River, Ore., which won gold at the Great American Beer Fest 2012. If you’re in the Seattle area, it would be a crime not to mention Holy Mountain Brewing, whose lineup changes frequently but typically features mixed-culture and brett-fermented ales. American-brewed sours are relatively young as a trend, so I’d recommend a wide sampling of styles across multiple breweries. Regardless of personal taste, it’s a fantastic opportunity to try a variety of beers brewed with unique processes, inspirations and market focus.