st]. We also tasted citrus in a lot of the kveiks, we tasted rum and caramel flavours and we tasted almost mushroomy flavours as well. We’re still not sure what all those favour compounds are, and we may very well find that there are some unique ones made by kveik that are not made by other yeasts.”
Another thing Escarpment noticed, Preiss says, is that there seems to be two main groups of kveiks, looking at their genomes, which correspond, for the most part to the geography of the region where kveik is found: one group, including Hornindal, to the north of the Jostedal glacier, the largest glacier in Europe, and the Sognefjord, Norway’s largest and deepest fjord, and the other group, including Voss, to the south of those two important geographical barriers. “It suggests that though they may have had a common ancestor, they evolved separately because of the geographic isolation of the regions they are now mostly found. The glaciers and the fjords in Norway create barriers which made it hard for people to move around in the past. We don’t often see these kind of geographic links in the genetics of yeast cultures.” Garshol points out that the divide also matches a split between brewing processes: to the north, almost entirely raw ales, with the wort unboiled; to the south, most brewers boiling their wort. (For a proper discussion see Garshol’s own blog here)
The unanswered question at the moment is where kveik strains fit on the yeast family tree. A study released in 2016 by the Flanders Institute for Biotechnology and the University of Leuven in Belgium found that all commercial beer yeasts come in two strains, Beer One, which dates from the late 1500s or early 1600s and Beer Two, dating from the 1650s or so. So far Preiss and his team at Escarpment have only been able to make a rough fingerprint of the kveik strains they have, “which is not very high-resolution, but it’s typically accurate and it can give us an indication of the genetic relatedness of different yeasts. So what we found when we took this approach is that the kveik yeast across different samples were more closely related to each other than they were to the other strains of domesticated ale yeasts.
“Because of that, we think that the kveik may form a separate branch on the family tree of beer yeasts. That being said, if we go and look for the most closely related yeasts, it’s a group of strains that includes some Kölsch yeasts and English yeasts, as well as a Lithuanian strain we looked at. So it’s possible that all these yeasts have a common ancestor at some point in history. But we can’t say that confidently yet, without whole-genome sequencing.”
Finding out more with whole-genome sequencing is expensive – $1,000 or $2,000 per strain. “But we think that because of the way the kveik have been maintained, and maintained for much longer, they haven’t been stuck in a lab for 100 years, this may be a new way for us to study yeast domestication without necessarily studying the commercial yeasts,” Preiss says. “We applied for a grant, and I’m happy to say that we did get funding to do the whole-genome sequencing for these kveik strains. We can hopefully have an answer some time in the spring, and hopefully say for sure that the kveik are a separate line on the family tree and have a little bit of a better idea of exactly where and when they broke off from the other beer yeasts. We’re using these Norwegian yeasts to really push brewing science, and yeast science, forward.”
Another question to be answered is: are there other yeasts like these? “Yes, of course, in Lithuania, and Russia and probably in other places,” Preiss says. “That’s a really exciting opportunity, to maybe look at these and start to understand these other yeasts that aren’t industrial and aren’t wild. The term I’ve started to use is ‘landrace yeasts’, which I think works well for an organism that’s been domesticated traditionally, without the involvement of industry, and because of that unique cultural framework, it has become genetically distinct from the other populations of that species. It s