Two of homebrewers’ greatest woes are time and temperature. More specifically, the time it takes per batch for beer to ferment; and controlling the fermentation temperature during that time. This can be especially harrowing for nascent homebrewers — after all, few want to wait four weeks to taste their creation — and even more so when starting out, investing in the space and cost required for a temperature-controlled fermentation chamber is unlikely.
Meet kveik: an ancient yet trendy yeast whose unique characteristics reduce these major roadblocks of fermentation. Originating in Norway, kveik and its super-fast, super-clean, super-warm fermenting strains are catching on with homebrewers and professional brewers around the world.
Why kveik is unique
If a homebrewer mad scientist could design a special yeast in a lab, it might just be kveik. Genetically different from typical brewer’s yeast (saccharomyces cerevisiae), kveik is like Frankenstein’s monster for fermentation, seemingly built out of the best parts of other yeast strains. It has all the alcohol and heat tolerance of a Belgian yeast, with none of the off-flavors; the slightly fruity ester profile of American ale yeast, with a clean finish; plus a fermentation speed that brewers only dream of, and likely have never seen before.
“The fastest successful fermentation I’ve had [with kveik] was approximately 48 hours,” says homebrewer Chris Hunter, an active member of the Brewing with Kveik Facebook group. Fermentation speeds such as this mean it is possible to go from mash tun to pint glass in less than 10 days. Compare that to an average of 20 days before most homebrewed ales are ready to drink, and it’s easy to see the appeal of kveik.
At the same time, speed does not mean compromising quality. James Sheehan, of Yeast Side DC homebrew club, says his kveik beer was ready to drink in less than a week. “I brewed on Thursday and was drinking the beer on Sunday,” he says. “With that said, I’m usually not pushing speed for the sake of pushing it. Kveik beers are good and very drinkable right away, but they do get better after another week or two of conditioning.”
Kveik flavors and uses
Though kveik produces no smoky, spicy, or solvent-y off-flavors normally associated with fusel alcohols and phenols that occur at high fermentation temperatures, it still has a distinct flavor profile. Most strains of kveik are described as fruity, orange being mentioned the most.
This flavor profile lends itself perfectly to the ever-popular NEIPA, as well as other styles typically made with American ale yeast and citrusy hops. Sheehan has made a wide variety of styles using kveik strains, including both hoppy styles and classic styles such as cream ale, bière de garde, and altbier. The bière de garde was “on the darker side, malt-forward, no phenols, but with some moderate fruity esters that were really nice,” he says.
Carrie Soom, secretary of The Brewminaries homebrew club, based in New York City, believes kveik even works for tropical stouts. Soom says, “I made a chocolate orange stout with Voss kveik that was delicious.” She’s also used kveik for IPAs, blonde ales, and kettle sours.
Another strain of kveik, called Oslo, has been described by commercial distributors as having a clean, lager-like fermentation profile. Many homebrewers note that while Oslo does have the most subtle of kveik’s fruit characteristics, the flavor is a touch too pungent to convincingly replicate a lager.
Along with lager, styles that don’t quite jive with kveik include those that require spicy phenols — the signature clove flavor of German wheat beers, and the peppery zing that denotes a saison, for example, require their own specific yeast strains.
More benefits of kveik
Another factor that speeds up the process of fermenting with kveik is that very little wort chilling is required. Kveik ferments at around 85 to 100 degrees Fahrenheit, with some homebrewers even reporting successful fermentation up to 109 degrees. (Soom, for one, says, “I tend to pitch around 90 degrees and just let it rip!”). High-temperature fermentation eliminates the need for ice (often pounds of it) and time getting fresh wort to cool — making the journey from boil to sub-70 degrees before pitching much swifter. As Sheehan points out, this warm-fermenting yeast also saves water, and about $50 on a wort chiller, making homebrewing that much more affordable and sustainable.
Another benefit of fermentation temperatures this high is that the yeast cells can maintain the proper temperature simply from the heat put out by their own metabolism activities. This means there is no need for special cooling or heating equipment for fermentation, nor for finding the coolest possible place in the house for fermentation — essentially, you can stick the fermenter anywhere it will fit, and the wort will ferment without noticeable off-flavors.
The only time the temperature may need special attention is in the winter months — Soom, for example, says she may put a sweatshirt on her fermenter to insulate it slightly. Hunter, who posts regularly in the kveik Facebook group, says he ferments in an outdoor shed where temperatures can dip below 30 degrees, and a simple heating pad and a sweatshirt around his fermenter are enough to keep the wort in kveik-friendly conditions.
Setting kveik up for success
Kveik is largely self-reliant. Though kveik can take care of itself for the most part, there are a few things homebrewers can do to set up the yeast for the most successful fermentation. Because of its very high rate of activity, kveik performs better with more yeast nutrient than a typical saccharomyces cerevisiae.
“I would suggest that [first-time brewers] double the amount of yeast nutrients called for by nutrient manufacturers,” says Drew Jackson, who has been homebrewing for more than a decade.
Pitch rates are another element to consider: Brewers in kveik’s homeland of Norway traditionally pitch very low cell counts, or what brewers call “under pitching.” However, Hunter advises that brewers not severely under pitch for their first few fermentations with kveik. “Pitching less than normal rates is fine, but if you are going to do it, make sure to aerate your wort and add nutrients to avoid stalling or off-flavors,” he says.
Finally, kveik does best in high-gravity worts, or those that have lots of fermentable sugar and will end up with more than 5 percent alcohol. “Kveik really thrives with high-gravity beers,” says Soom, who admits her only kveik “fail” was with a batch that had a lower original gravity. “It may not have been super happy fermenting a 4 percent mead, even with all the yeast nutrient I gave it.” (She ended up adding American ale yeast to finish out the ferment.)
Session ales will end up too dry, and with a thin, watery body because of the speed and efficiency of attenuation (the conversion of sugars into alcohol and carbon dioxide via fermentation). For example, Sheehan says, “a cream ale I wanted to be 5 percent ended up being more like 6.5 percent.” Because of the over attenuation, the cream ale was unexpectedly dry and packed more of an alcoholic punch.
The keys to success when using fast-fermenting kveik are extra nutrient, not-too-low pitch rates, and a high-gravity wort to start. With these tips, kveik fermentation will be a success. For those ready to refine their kveik techniques, Lars Marius Garshol’s blog is a preeminent source for information on kveik used by many homebrewers.
Published: May 27, 2020