Whole genome sequencing of traditional Norwegian farmhouse yeasts (kveik)

Kveik, a group of traditional yeasts used in farmhouse brewing in western Norway, represents an important element of intangible cultural heritage, preserved through generations of rural brewing practice. Previous genetic analyses have identified kveik as a distinct group within Saccharomyces cerevisiae, related to modern beer yeasts but with uncertain genetic origins. Here, we present comprehensive genomic analyses—including phylogenetics, population genetics, mito-genomics, and Ty1 retrotransposon profiling—which position kveik as an early-diverging lineage within domesticated S. cerevisiae. This divergence appears basal and lacks evidence of admixture, making kveik the second-most basal split after Asian fermentation lineages. Based on phylogenetics and divergence time estimates, we hypothesize that the common ancestor of beer, kveik, and most other wort-fermenting domesticated strains emerged from a nearly panmictic ancestral population between 4000 to 8000 years ago. Our findings indicate that kveik is paraphyletic and basal to other domesticated strains, supporting the notion of a single monophyletic origin of all domesticated S. cerevisiae. Kveik yeasts represent a relic of early domestication, that may have been shaped by ancient human migrations and the spread of agriculture. They likely comprise some of the oldest domesticated lineages in continuous use, connecting endangered intangible cultural beer brewing heritage to an early genetic origin. Note: Norwegian place names have been transliterated to their closest ASCII representation.