The Fjord Fusion

Escarpment Laboratories (Guelph, Ontario) and the University of Guelph in Canada have analyzed the genomes of different kveik yeasts, which sometimes have ten or more different strains of Saccharomyces cerevisiae in one culture, and found that the yeasts appear to be the result of a mating perhaps centuries ago between a strain from the “Beer 1” family, to which most commercial brewing yeasts belong, and another less closely related yeast, an event Richard Preiss, cofounder of Escarpment Laboratories, jokingly refers to as the “fjord fusion.” Plotting the different halves of the kveik genome ends up with it occupying two very separate spots in the “family tree” (see the red names in the diagram).

“About forty different cultures have been collected from different parts of western Norway,” Preiss says. “They all consist mostly of Saccharomyces cerevisiae yeasts. Remarkably, all of them turn out to be more closely related to each other genetically than to other yeasts. The kveik yeasts form a distinct branch of the tree of beer yeasts.”

While kveik belongs to the Beer 1 family of brewer’s yeasts, together with most British, American, German, and Belgian top-fermenting beer yeasts, kveik yeasts differ slightly from these in that they appear to be the result of a Beer 1 yeast mating with possibly a wild yeast.

“This means that kveik yeasts potentially have two distinct parental lineages [haplotypes], one being an old Beer 1 yeast and one with unknown provenance,” Preiss says. “The unknown yeast could have been something used in Norway prior to extensive trading with continental Europe, which is presumably how the Beer 1 ancestor arrived in Norway. Additionally, kveik yeasts are highly heterogeneous [high degree of genetic diversity within the group] and have some genetic mutations unique to them, which might be relevant for alcohol and temperature tolerance.” —Martyn Cornell