I have an unexpected update on my dried kveik experiment. My foray into Kveik brewing began back in 2016, and while I had forgot this until recently, I tried drying Kveik in a very primitive fashion after my first attempt at a Norwegian farmhouse ale.
I passed this beer out at my homebrew clubs 2016 advent exchange. More as a gimmick than anything, I included a low-budget version of the traditional Kveikstokker (yeast log) with some of the Voss kveik dried on it. This yeast “log” was nothing more than a 2 cm piece of wood dowel that I rolled in yeast slurry, let air-dry on the kitchen table, and then attached to the bottle in a small bag.
So imagine my surprise when one of my club members posted on our forum that he threw this yeast log into a starter and it worked. According to my brewing notes it has been 965 days since I dried that kveik. As in 2 years, 7 months and 23 days.
I have no idea what the viability of the yeast was, but there was enough viable yeast to make it work.
It looks like my current prediction of a 3-year viable lifespan of dried kveik slurry is not wrong…and is probably an underestimate.
EDIT (11/7/2019, 11:01 AM): The brewer who has resuscitated this yeast has provided me with additional information on how the yeast was stored. In his own words: “I’ll embarrassingly add that I did not take care of the log at all. While it remained in the baggy the entire time, it also sat on a shelf, fully exposed and with zero temp control in the fieldstone basement. Winter ambient ~50F. Summer ambient ~63F with variable humidity.”