What is Kveik?
You may have come across kveik while perusing your beer options and wondered what’s behind this trendy new beer style. It turns out that kveik (pronounced “kah-wike”), is not a new beer style at all, but refers to a unique family of ancient yeast strains originally used in Norwegian farmhouse ales. Kveik, a western Norwegian slang word for yeast, designates a collective of high-heat-tolerant yeast strains capable of producing clean beers at unusually high fermentation temperatures without hot alcohol flavours, medicinal or funky aromas that other ale yeasts would produce in the same high temperature range.
From Norway to North America
Recent interest in Scandinavian farmhouse ale is generally attributed to Norwegian Lars Marius Garshol’s chronicle of his own fascination with farmhouse beer – piquing the curiosity among North American brewers. Garshol, an Oslo-based scientist and blogger, was introduced to kveik by brewer Sigmund Gjernes, whose own kveik yeast strain, Voss, has been handed down through generations of homebrewers outside of Voss, Norway.
In 2014, Gjernes invited Garshol to brew with him and Garshol kept detailed notes on Voss’s resilience and ability to ferment at very high temperatures. Garshol’s comprehensive notes inspired Lance Shaner of Omega Yeast Labs, to reproduce kveik yeast for commercial distribution in the United States.
Kveik versus other Ale Yeasts
Most ale yeasts work best at temperatures between 13 to 21 C, and will take roughly seven days to ferment an ale at 5% ABV. Higher temperatures will accelerate fermentation, but most yeasts will also produce off-flavours as a by-product of high-temperature fermentation. In general, yeasts will also start to die at temperatures above 40 C or with an ABV higher than 10%.
Kveik yeast, by contrast, can ferment at temperatures as high as 36 C, without producing off-flavours and can also tolerate alcohol temperatures over 10% without giving off hot and harsh alcohol flavours. At higher brewing temperatures, kveik can ferment a 5% beer in as little as 48 hours, which is considerably faster than a typical ale yeast.
Omega Kveik Profiles
Omega currently has three kveik yeast strains. The first available yeast strain isolated by Garshol was called HotHead, and has honey-like aromas with overripe mango. Voss, from the Gjernes farmhouse, imparts moderate orange citrus and Hornindal, another Norwegian farmstead yeast strain, shows strong pineapple, dried fruit, and stone fruit.
An incredibly versatile type of yeast, kveik can be used to make beer styles including IPAs, porters, stouts, bitters, milds, farmhouse ales, as well as clean and light “faux” lagers. Because Kveik strains are POF – (phenolic off flavour negative), they are not used to produce phenolic beer like hefeweizens and rauchbier. It is kveik’s unique ability to withstand high fermentation temperatures that has given brewers the freedom to approach fermentation differently and to reimagine traditional styles of beer.