Some Kveik It Hot

We’ve had a few years now to play with those previously unknown Norwegian farmhouse cultures. What have we learned from the world’s most versatile yeasts?

The world’s brewers have had a few years now to play with the unusual, high-performing, previously little-known heirloom yeasts from Norway. So, what have we learned?

THE WEATHER WAS BRISK

in the Dyrvedalen valley, in Norway’s Voss region, but it was warm inside Bjørne Røthe’s wooden shed. At its heart was a steaming, bubbling kettle of magic potion, directly heated by a log fire.

The kettle was almost full, but lautering continued—slowly—off to the side. We knew there were juniper branches in the bottom of that mash tun, and we saw more piled in a trailer out front. The smell of them was in the air, mingling with sweet wort. Every now and then, Røthe would take some of those additional runnings and add it to the kettle—why waste a drop?—which boiled and reduced for more than six hours to make his potent version of Vossaøl, or Voss ale, which would finish at 10 or 11 percent ABV.

He shared some from a previous batch. First, we tasted it cool, then warm—he heated it in a cup by setting it in the boiling wort. It was equally delicious both ways: deeply malty from the long boil but not thick or cloying, getting balance from a gentle bitterness and distinctive twist of orange-like citrus character. Røthe poured it into wine glasses for us, and it was flat like wine—totally without carbonation. This

true barleywine was clean in its profile, and I had to ponder how many beers would taste as good warm as they do cold while being as flat as a pancake. Not many.

The beer was a marvel in itself, but my moment of awe came when Røthe explained the fermentation. It would ferment at about 37 or 38 degrees, he said, and be ready to drink in two, maybe three days. Hmm.

It must have been a few seconds before I remembered we were talking Celsius, then had to work out the math. This beautifully clean, strong ale would be ready to drink in just a couple of days—and it would get there by fermenting around 100°F.

That was nearly two years ago. I had heard about kveik; I’d read the blog of Lars

Marius Garshol—who allowed me to join him on that trip to Dyrvedalen—and I had tasted a few beers made with it. But I’d been more interested in the idea of farmhouse brewing and heirloom yeast. Until tasting Røthe’s Vossaøl, I didn’t fully grasp the significance of what that special family of yeasts can do—or the potential it has to transform brewing as we know it.

At the very least, kveik already has become a useful tool in the box of amateur and craft brewers around the world. Yeast labs have made various strains more widely available over the past few years. Now, I can’t help but think of us—hundreds of thousands of homebrewers and 8,000-plus commercial breweries in the United States alone—as an unprecedented sort of open, collaborative laboratory to really explore the potential of what these unique creatures can do.

Kveik 101

First: how to say it.

“Many non-norwegians struggle with how to pronounce ‘kveik,’” Garshol writes in his book, Historical Brewing Techniques: The Lost Art of Farmhouse Brewing. “The correct, Norwegian pronunciation is close to the English ‘quake’ but with a ‘v’ sound. If you try saying something like ‘qvake’ or ‘kvike’ you will get fairly close.”

Another thing: Kveik is really just another word for yeast. It’s not a style of beer, though we shouldn’t ignore the unique, Norwegian farmhouse ales that have kept it going. Instead, kveik has come to mean a whole family of genetically similar

Researchers have so far identified at least 24 different kveik cultures, among many other farmhouse yeast cultures. So far, each culture has been found to contain multiple yeast strains—sometimes as many as 10.

cultures from western Norway, handed down, continually selected for quality, and often shared among the farmhouse brewers there. Researchers have so far identified at least 24 different kveik cultures, among many other farmhouse yeast cultures. So far, each culture has been found to contain multiple yeast strains— sometimes as many as 10.

No other yeast ferments like a kveik culture.

Here are the main things to know:

▪ They tolerate a wide range of temperatures, performing well from 70 to 100°F (21 to 38°C) or higher.

▪ They ferment quickly, often within 48 hours at the higher temperatures. ▪ Unlike some temperature-tolerant Belgian yeasts, for example, they do not produce spicy phenolics at those warmer temperatures. (In technical terms, they are phenolic off-flavor negative, or POF-.) ▪ Also unlike some of those saison cultures, they are not diastatic—meaning they won’t keep on chomping dextrins until there’s nothing left, leading to possible over-attenuation.

▪ They are, however, good attenuators, often up to 80 percent.

▪ They tolerate higher alcohols better than most yeasts, comfortable up to 12 percent ABV but apparently able to handle up to 15 or 16 percent alcohol.

▪ They generally ferment cleanly, without obvious off-flavors, with their main flavor contribution being subtle fruity esters that can help accentuate fruit or hops.

In short, kveik is dynamic, versatile, and forgiving—potentially a dream for any brewer who is looking to experiment or isn’t necessarily married to using a particular yeast strain for a matching beer style.

On the topic of styles: The recently “rediscovered” farmhouse styles of Norway are certainly worth brewing and drinking. Broadly, Garshol separates them into two traditions, with names used by the farmer-brewers themselves:

▪ kornøl, literally “grain ale,” which is also a “raw ale”—fermented without boiling. ▪ heimabrygg, literally “homebrew,” which is boiled and tends to be relatively strong.

Bjørne Røthe’s kveik-fermented Voss ale that I drank in Dyrvedalen was part of that heimabrygg tradition—and thanks to Garshol, we include a recipe (page 59).

For much more about these traditions and many more in Northern Europe and the Baltics, you’ll want to add Garshol’s Historical Brewing Techniques to your personal

“For some of our more saison-like kveik beers, I really like the citrus note that Voss adds,” Saller says. “For IPAS—I mean, we’ve done some great IPAS with Voss, but also the more tropical-fruit character of Hornindal sometimes really helps kick the popular hop flavors of today up a notch. Also, I find Hornindal maybe adds a teensy bit more perceived acidity, which can help structure juicy IPAS.”

Saller says he’s eager to try Omega’s new Lutra strain, which was isolated from the Hornindal culture. The lab describes it as “shockingly clean” and “perfect for brewing a refreshing pseudo-lager without the lead time of a lager.” (With descriptions like that, it’s not hard to imagine commercial breweries—where time and fermentor space are, literally, money—taking advantage of these strains for a broader range of styles. There are interesting semantic and ethical considerations in whether you ought to explain that you used kveik if you’re selling a “pilsner,” for example.) For Saller’s part, he says he’d like to try it in a mixed-fermentation beer, after Lactobacillus acidification and before some aging with Brettanomyces.

Another brewery that’s been known to use kveik is Rockwell Beer in St. Louis. Two years ago, while its brewers and founders were waiting to launch the business, they passed the time by testing pilot recipes on a homebrew kit in a non-air-conditioned industrial space. As St. Louis summer temperatures exceeded 90°F (32°C) and with the kveiks becoming more available, it was the ideal time to start playing with them. Jonathan Moxey, the head brewer, says that a couple of kveik cultures remained to become Rockwell mainstays—especially for fruited sours and high-strength beers.

“The main reasons we’re using kveik for ‘quick sours’ such as Berliners and goses, as well as high-gravity beers such as barleywines and imperial stouts, is for complementary ester production and the quality of the alcohol created,” Moxey says. “Our go-to with the quick sours is the lab-isolated Voss strain from Omega, because it provides a clean citrus ester that works well with fruit additions. We use the same strain for Jumbo, our 15 percent ABV imperial stout, because it can handle the initial starting gravity and reach our desired attenuation without the production of fusel alcohol.” Notably, Jumbo starts at 33°P, or about 1.144.

“The ester contribution is minimal,” Moxey says, “or it’s masked by the roasted malt character. For Poking Bears, our English-inspired barleywine clocking in at 13.4 percent, we use the lab-isolated Hornindal from Omega. It’s contributing a lot of the stone-fruit and dried-fruit notes I like in those beers and, again, is providing a really clean alcohol at a high ABV. There’s no fooling about the strength, but the heat is minimal.”

The kveiks can work for lighter styles, too, though the ester contribution may seem louder up against more elegant malt and hop profiles.

Jereme Zimmerman, homebrewer and author of Brew Beer

Like a Yeti—about homebrewing with various traditional techniques—also has been experimenting with kveik. He received two cultures—known as Stalljen and Geiranger—from Mika Laitinen in Finland, another writer with deep interest in traditional Nordic brewing. “Stalljen is great for imparting a refreshing, fruity complexity to lighter beers like blondes and wheats,” Zimmerman says. “Geiranger seems to accentuate maltiness and imparts an almost candy-like flavor. I tend to use Stalljen more with light pales and ‘pilsners’ and Geiranger more with rich, aromatic malts—caramels, ryes, Maris Otter.”

Zimmerman says that the kveiks can ferment a bit more slowly in the lighter beers—they seem to prefer the higher-alcohol environments—but also that some nutrients can help them along.

“As for temperature,” Zimmerman says, “I pretty much always add kveik when the temperature hits between 90 and 100 [°F

(32 and 38°C)]. I keep the fermentor wrapped in a blanket or set it on the back porch if it’s hot out. I’ve found that once the fermentation gets going, there’s less concern about keeping things hot on a small homebrew scale, as the kveik does a lot of the work. If I hold my hand over the kräusen, [I can tell that] kveik definitely produces a fair amount of heat compared to other yeasts.”

Still Greater Potential

Somehow, it’s been only about seven years since Garshol started writing about kveik and Norwegian homebrewing traditions on his blog—capturing the attention of brewing geeks around the world, while getting hooked himself on rediscovering what seemed to be a forgotten realm. On a Zoom call connecting Missouri with Oslo—not quite two years since our visit to Dyrvedalen—i ask if he ever imagined the degree to which kveik would catch on.

“In one way, I expected people would be interested, given the story and the fact that it was so unusual,” Garshol says. “But it’s taken off far more than I ever expected, I have to say. Which I guess is partly because it’s not so different from the yeast that people normally use. You know, it produces clean flavors, maybe a little more fruit. But it has these very attractive properties, so you don’t have to worry about the cooling, and it’s much faster, and you don’t have to let it mature as long.

“So, it’s a very practical yeast and very forgiving and easy to use.”

Meanwhile, yeast labs are still digging through these treasures, isolating strains that may handle certain kinds of beers better than others—as with Omega’s Lutra and Escarpment’s Krispy (“a special blend of kveik yeasts selected by our lab wizards for optimal crispiness and crushability in beer,” Escarpment says).

“There’s a lot of more exploration to do,” says Lance Shaner, founder of Omega Yeast. “I think these clean-fermenting ones kind of exemplify that. I mean, the natural cultures out there are mixed cultures. So, who knows what’s hiding within these mixed cultures? And purists like to think there’s some special magic in the original mixed cultures—and maybe there is—but there’s also I think a lot of gems hiding within them. Plus, there’s a lot more mixed cultures out there, so there’s still a lot of exploration to do.”

Of course, this important and useful research isn’t only happening in the laboratories under the microscopes. It’s also happening in our own brewhouses, garages, and kitchens, as we each unleash this ancient, fiery Northern creature to see if we can teach it new tricks.