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Kveik yeast had been on our radar thanks to some of the early reports brewers were offering in regards to turnaround, fast fermentation, and low ester and phenol profiles. We toyed with the idea a bit and finally got our hands dirty in September 2018 when Sean Buchan of Cerebral Brewing (Denver, Colorado) joined us for a collab. We riffed off our standard IPA recipe and built a pretty cool hops bill that we thought would play off of the Omega Hornindal Kveik yeast. None of us had used it before, so we were shooting in the dark.

Our pitch rates were pretty standard—we didn’t want to go too short—and we kept the oxygen in the wort pretty standard. We wanted to use it as a baseline to judge how this new (to us) yeast would perform in our cellar. We’ve brewed with California Ale yeast and English Ale yeast for years and have a very good idea of how they will perform but had no track record with impacts of temperature and other factors on how the kveik yeast would perform.

Once fermentation started rolling, it took only 4 hours for us to see the gravity drop. We were just floored at that point. One of the important advantages of these yeasts is the warm temperature range they ferment at, and we wanted to explore that, so we knocked out the wort at 80°F (27°C). It was freaky seeing that going through the system, but we let it ride, and we set the temperature jackets on the tank at 95°F (35°C) so it wouldn’t get too crazy, but by the next day it was already at 95°F (35°C) and had fermented 10°P (1.040 SG) from the starting gravity in just 12 hours. It finally hit terminal gravity at 5°P (1.019 SG), so it was pretty predictable using our IPA recipe as a base.

The flavors that we got were really cool—tasting beer out of the tank at 90°F (32°C) is really strange. You’re not too sure what you’re totally getting, but right away we were getting intense tropical notes—resinous funky pineapple, sweeter mango/papaya, and a really interesting citrus profile that reminded us of Grand Marnier liqueur with some sweetness behind a brandy note. That was right before dry hopping, so we were skeptical about whether that intensity would remain, but once we dry hopped with a blend of Citra and El Dorado, it started to marry with those tropical and citrus notes.
The beer was out of the tank in 14 days—a little faster than our standard tank residency for IPA, but to be able to get through fermentation and into dry hopping that quickly was exciting. We didn’t experiment with dry hopping during active fermentation, as we weren’t sure how the high temperature would affect it and wanted to isolate the yeast as a variable first. Once it hit terminal, we chilled the tank to a comfortable 70°F (21°C) and got our dry hop going.

It proceeded as usual from there, as we observed the turbidity and sedimentation in the tank. We got a pretty healthy yeast harvest off of it, which surprised us as anecdotal reports from brewers using other strains were all over the place in regards to flocculation. We hard-crashed the tank and got a decent amount of yeast off it.

Looking at a glass of it now, 4 1/2 months later, I’d describe it as a moderate haze with a bright orange body and light-to-medium turbidity, but it’s not the milky quality that some consumers expect. Flavor-wise, the beer is wildly different now than when fresh. Around the brewery, we shared a similar sentiment—drinking it fresh, doing forced diacetyl tests, and having it on taste panel, none of us knew what we were getting into.

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Trying to describe what this IPA tasted like put everybody to the test. It took a month to 6 weeks after it was canned and on draft for it to really come together and pull out the tropical and citrus character we found in the fermentor where some of the bright grassy character from the dry hop had faded a bit.

Coming back to it now, it shows a touch of age, but that slight liqueur brandy note is lingering on the nose. It has a strange green note—okra or asparagus—and I’m not certain whether that’s a reflection of the hopping or how the yeast is transforming.
We used the yeast a second time in a completely different beer and saw that orange liqueur character as a jumping-off point for something different—a winter warmer–style spice ale inspired by mulled wine.

There’s a Scandinavian mulled wine with a similar spicing profile as standard American mulled wine but with almonds and cherries in it as well. So we built a fruited spiced winter warmer around the orange character and gave it some holiday spices and tart cherries and grape must, then fermented at 90°F (32°C), and sure enough, that orange liqueur character came back.

We used that as a test of attenuation as well to see what the alcohol tolerance of the yeast would do. That beer ended up finishing at 11.5 percent ABV, but with no fusel alcohol on the nose, and it wasn’t hot on the palate, even after ripping through such a warm fermentation. It took a similar amount of time to really settle in to itself. After about a month in the tank lagering, it started to meld, and even now drinking it 3 months later, it has some alcohol sweetness, and you get the spice character, but the interplay between the fermentation and the fruit is really cool.

We’ve scheduled another IPA batch upcoming, using the same recipe and same fermentation schedule as the first, but changing up the hops a little bit to see what that does. Ultimately what we’re hoping for is R&D for future releases and a possible larger production scale-up. We’ll see if the market is ready for easily accessible IPAs fermented with a Norwegian farmhouse yeast.

Exploring the temperature range is going to be key with these yeasts. As far as building a flavor profile around fermentation, there’s still a lot of ground for us to cover to know and have expectation of how they will perform. By brewing IPAs with kveik, we’ve almost taken what we’ve learned in the past few years of having the yeast available and jumped 100 steps down the road. Now I suspect we’ll take some steps back and explore its versatility in other styles.

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