Kveik: The Little Yeast Strain That Could

If you’ve been paying attention to the beer landscape in the last few years, you’ve almost certainly seen the word “Kveik” pop up at one of your favorite bars or taprooms, possibly alongside words like “Norwegian farmhouse ale.” These words, however, like so many other labels in the beer world, don’t necessarily summon an accurate expectation from the drinker of what a “Kveik beer” will be like. In particular, “farmhouse ale” might put you in the mindset of a classical, Franco-Belgian saison, but Kveik is something else entirely. In reality, this little-known, traditional ale yeast has proven incredibly adaptable to modern brewing styles, and has the potential to be useful across a wide range of styles for both homebrewers and professionals.

In short, the word “Kveik” simply means “yeast” in the Norwegian language, meaning that referring to it as “Kveik yeast” may be a bit redundant. But this is not a standard strain of saccharomyces cerevisiae, of the sort you may have been purchasing from a homebrew shop for the past 20 years. Although Kveik is indeed Saccharomyces rather than wild brettanomyces, it differentiates itself with properties that make it strange and unique.

Take fermentation, for instance. Kveik has the distinction of being viable in an incredibly wide range of fermentation temperatures, which sets it apart from comparable ale yeasts. In particular, it can ferment much, much warmer than other varietals, at temperatures that exceed 100 degrees, while apparently not struggling at all in terms of viability. Stranger still, though, is the fact that swings in temperature of fermentation don’t seem to particularly affect the flavor profile of Kveik beers—it produces beers that taste more or less the same when fermented at 70 degrees or 100 degrees. Those who have any brewing experience at all know that this sounds almost impossible, as most of the popular commercial ale yeast strains, such as Sierra Nevada’s famous Chico strain, behave very differently when the temperature raises even 5 or 10 degrees. Not so with Kveik, and this versatility has a lot of brewers very excited. At the same time, it represents perhaps an even more exciting find for homebrewers, who may lack means of accurate temperature gauging or precise temperature control during fermentation.

But it gets even weirder. Kveik yeast also naturally dries into flakes, making it easy to store without liquid, and making inoculation potentially as simple as just adding some dried Kveik back into a carboy of cooled wort. It also flocculates heavily, meaning the yeast drops out of suspension, allowing brewers to separate it easily, and making it easy to produce either clear or hazy beers as desired. Coupled with a relatively mild, somewhat fruit-forward flavor profile, it makes Kveik the hidden Swiss army knife of ale yeasts. In fact, its properties are potentially so valuable, it’s a bit of a wonder if took so long for this old-style yeast to be discovered and co-opted by U.S. brewers.

Now, though, it’s clear that Kveik has arrived, in a variety of different strains. The yeast is having a moment at small U.S. craft brewers from coast to coast, and will be celebrated by more than 30 breweries at the inaugural Kveik Fest in Chicago on Saturday, Sept. 7. Sponsored by Chicago’s Omega Yeast, who were among the first to supply Kveik to U.S. breweries, and organized by head brewer Ben Saller of Burnt City Brewing, the event will be hosted at brewery collective District Brew Yards (which houses Burnt City), with all-you-can-drink Kveik tickets going for $75 a pop. Speaking with Paste, Saller described himself as an enthusiastic Kveik fan, who has used the yeast strain to make quite a few very different beer styles at Burnt City in the last few years.

“The different strains of Kveik yield different flavors, which makes some of them perfect fits for specific styles of beer,” Saller said. “In general they’re fruity, but without banana esters or clove-like phenolics that you’d get from Belgian ale yeast. Some give citrus notes; others produce flavors that are more like pineapple or mango. These flavors are fairly subtle; they’re not strong enough that you can’t use Kveik strains for an imperial stout or barleywine, but I love how they accentuate hoppy beers or farmhouse styles.”