Rise of the Super Yeast: Will an ancient Norwegian yeast revolutionize American craft beer?

Yeast Ring Photo Via Lars Garsohl Blog

Wooden rings covered in kveik yeast are used in Norwegian farmhouse breweries // Photo by Lars Marius Garshol

In early 2017, Lance Shaner received a package in Chicago postmarked from Norway. With great anticipation, he delicately opened the box, revealing contents that had the potential to shape the trajectory of modern craft brewing.

The product wasn’t a new one, though. It was ancient. To Shaner’s relief, the contents had survived their journey. And while the recipient was excited for the business angle of the product, the sender, Lars Garshol, was content knowing that the rich brewing tradition of his country was about to hit the world stage.

Garshol, a scientist and blogger from the Oslo area, single-handedly brought the spotlight upon kveik (pronounced “kwike”), a family of yeasts that has been handed down through generations of homebrewers outside Voss, Norway. He was introduced to it by farmhouse brewer Sigmund Gjernes, who considers kveik his family’s own strain. Gjernes invited Garshol to brew with him in the spring of 2014. While brewing, Garshol kept detailed reports and reflections on this hardy strain, capable of rapid fermentation at very high temperatures. It was these notes that inspired Shaner to propagate kveik for commercial use in the United States.

Shaner is co-owner of Omega Yeast in Chicago. He was confident from the moment his mail arrived that the yeast would be a huge success in the U.S. The brewers at Dangerous Man Brewing Company in Northeast Minneapolis, on the other hand, weren’t so convinced.

Dangerous Man co-owner and head brewer Rob Miller recalls the moment Shaner stopped by with his new project. “Yeah, I was skeptical,” says Miller. “We thought, maybe, it was too good to be true.”

In order to understand the remarkable nature of kveik, you must understand the rules by which most yeast play. Ale yeasts like to do their work at about 55 to 75 degrees Fahrenheit. At these temperatures, most yeasts take around seven days to ferment a 5% ABV ale. Crank the temperature up higher than this range and ale yeasts will ferment faster and hit that mark in less time; however, with rare exception, they will produce loads of off-flavors (compounds that are unpleasant in beer) in the process. If the environment is increased to 104 degrees, yeasts will start to kick the bucket. Additionally, many strains don’t like to be bathed in alcohol—they produce it, yes, but many won’t tolerate over 10% ABV; the majority of yeasts couldn’t stand up to the alcohol content of the average barleywine.

Kveik, on the other hand, laughs in the face of these limitations. Not only can it withstand more alcoholic environments (the alcohol tolerances of Omega’s three strains range from 11–16% ABV), but they can ferment at temperatures as high as 98 degrees without producing off flavors. At these higher temps, kveik can ferment the same 5% ABV beer in as little as 48 hours—three to five days sooner than a typical ale yeast. Some can even survive 104 degree environments. “Some kveik start to die at those temps as well, but some will tolerate that temp and a little higher,” says Shaner. Results in hand, Shaner began the task of convincing brewers he was serious.

The brewing team at Dangerous Man recalls the first batch they made with kveik: a beer called Tarty Party, brewed in collaboration with Travail in July 2017. Soon-to-be Pig Ate My Pizza brewpub brewer Nat Moser was familiar with the Norwegian family of yeasts from his experience as a homebrewer. (When brewing at home, kveik is a dream since ambient temperature won’t harm fermentation.) Moser, who helped with brewing, swears by kveik—especially in the summer. Tarty Party was a hit, and Dangerous Man followed with Simzacca IPA the next month.

Yeast can impart very specific flavors to beers. In farmhouse-style ales, yeast-derived flavors like clove, citrus, and hay are desired, but in styles like IPAs, the flavors are often masked by hops. Because of its effect on taste as well as alcohol production, yeast strains are chosen carefully by brewers. To that end, Omega now has a trio of Norwegian farmhouse yeasts available that produce slightly different flavors.

The first available was HotHead Ale, so named to highlight its high fermentation temperatures. Omega describes it as having a “honey-like aroma with overripe mango, which is complementary to modern, fruity hops.” HotHead become like the beta strain for Omega: initially popular but now overtaken by the favored strains of Voss Kveik and Hornindal Kveik. Voss, from the Gjernes farm by way of blogger Garshol, imparts moderate orange citrus and general fruit characteristics; Hornindal, passed along from another farm, exhibits a strong pineapple, dried fruit, and stone fruit character that overlaps substantially with hop notes.

With those flavor profiles in mind, brewer and owner Mike McQuery of Half Pint Brewing Company in Waseca, Minnesota, uses Voss in his Fra Feltet Norwegian Farmhouse Ale and Hornindal in his Laura Pale Ale and Norway IPA. McQuery began experimenting with the two strains at his farm brewery not because of their superpowers, but because he is Norwegian and in the business of experimentation: Half Pint grows several varieties of hops, berries, herbs, and even Juniper, another traditional Norwegian brewing ingredient. The kveik family of farmhouse yeasts felt authentic to him.

“I came home and I researched how to use them,” he explains. The result was surprising. “They make a mess!” he says. The yeast starts the foamy process of active fermentation in two to three hours after being pitched into the fermentation tank, whereas typical ale yeast has a lag, or inactive phase, of up to 12 hours. (If repitched from a previous batch of beer, kveik can begin fermenting in as little as 20 minutes or so). McQuery doesn’t use any filtration at Half Pint and his beers take a few weeks to properly settle. He has also developed a meticulous process of fermentation, cold conditioning, and kegging. The three beers he made with kveik were Half Pint’s top sellers. And while McQuery says the quick turnaround offered by kveik is a major advantage for a brewery like his, which uses a 3-barrel brewing system, it’s the flavor and authenticity that he’s really after.

Back in Minneapolis, the pilot system at Insight Brewing is currently filled with a test batch of milkshake IPA using kveik. Head brewer Matt Anhalt has experimented with both Voss and Hornindal, with desirable results. “The hotter it’s allowed to go, the more citrus flavor you get, specifically lemon,” he says.

Anhalt heard Shaner speak during the brewer’s technical conference that precedes All Pints North, the annual waterfront Duluth beer festival hosted by the Minnesota Craft Brewers Guild. He knew he wanted to test the boundaries of the seemingly unbreakable yeast, and has since crafted several batches using a wide range of temperatures. In addition to the yeast’s resilience to temperature, Anhalt was struck by what kveik could do to lower energy costs, especially in the summer, when high ambient temperatures mean the cooling glycol would normally need to be running non-stop in order to accommodate the needs of other yeasts. “If it’s 85 degrees in the brewhouse, and I can let the tank rise to 85, I’m gonna do it,” he says.

Both Anhalt and Miller have been able to reduce the amount of flavor and aroma hops they use thanks to kveik, which could potentially reduce costs even further in the long run. They’ve also noted that fruit seems to be highlighted by the yeast. “Sometimes we’ve tasted a beer and thought the fruit had already been added,” says Lee Ankrum, a brewer at Dangerous Man. That would mean the volume of expensive fruit purees could be reduced in some cases.

While Insight sees the advantage of faster turnaround time in the face of growing demand, currently none of their flagships use kveik. Anhalt has done around a dozen experiments using the yeast in beers brewed on their pilot system with positive results, but he’s not keen to change a recipe that people know and love, unless it’s for the better. That said, he is convinced these Norwegian yeasts are here to stay. Insight recently distributed kegs of their Lovely Vision Brut IPA, made with kveik, to more than 50 local establishments.

More than being just another options for brewers, kveik represents an entirely new tool that as of yet has been unavailable to U.S. brewers. And those who have adopted these yeasts into their catalogue of ingredients are thus far very happy with them.

The brewers at Birch’s on the Lake and Birch’s Lowertown haven’t yet gone so far as to fully switch over to kveik, but have been experimenting with it and say they’re on board. Both locations, in Long Lake and Lowertown St. Paul, will have a Norwegian IPA on tap in February using the Hornindal strain. According to Birch’s brewmaster and owner Brennan Greene, they were inspired by Shaner’s passion for the ancient strain as well as reports of results from other breweries. While there is still a lot to be learned about kveik, the team at Birch’s say they wouldn’t be surprised if Hornindal or one of its relatives became a house strain.

After only about 18 months on the scene, kveik is a promising means to making quality beer. This family of yeasts provides a completely new, baffling set of rules for brewers to play by—being able to walk away from a just-filled fermenter, glycol jacket turned off, and expect a beer to be ready for conditioning after just one weekend is a total game changer. But at the end of the day, the flavors these yeasts produce have high potential to make both brewers and consumers happy. As for the emerging effects on the bottom line, that’s a fortuitous bonus.