Kveikur
Kveikur is a Norwegian word meaning "yeast" or "igniter," but in the context of brewing, it refers specifically to a family of domesticated strains of Saccharomyces cerevisiae yeast used in traditional farmhouse brewing practices, predominantly in Norway. Unlike commercially produced laboratory strains, kveik strains are typically mixed cultures of multiple yeast strains and sometimes bacteria, often passed down through generations of brewing families.
Kveik yeasts are prized for their unique fermentation characteristics, including:
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High Temperature Tolerance: Kveik strains can ferment successfully and cleanly at unusually high temperatures (often 90-105°F or 32-40°C) without producing excessive off-flavors like fusel alcohols. This makes them suitable for brewing in warmer climates or when temperature control is limited.
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Rapid Fermentation: Fermentation times are significantly shorter than with many conventional brewing yeasts, often completing fermentation within 24-72 hours.
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Flavor Profiles: Kveik strains offer a wide range of flavor characteristics, depending on the specific strain or blend. These can include fruity esters (such as citrus, tropical fruit, or stone fruit), earthy notes, and other unique flavors. Individual strains are often associated with specific families or regions within Norway.
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Alcohol Tolerance: Kveik yeasts generally exhibit good alcohol tolerance, allowing for the production of high-gravity beers.
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Storage and Re-pitching: Kveik cultures have traditionally been preserved by drying them on wooden rings or cloths, allowing them to be rehydrated and reused for multiple generations. This practice contributes to their long-term adaptation and distinct characteristics.
The recent interest in kveik has led to its increasing availability from commercial yeast labs, allowing brewers outside of Norway to experiment with these unique cultures. The use of kveik is seen as a way to add unique flavor profiles and simplify the brewing process, especially where temperature control is a challenge. It's important to note that "kveik" is a general term and each specific culture (e.g., Voss, Hornindal) will have its own unique characteristics.