In late July I was brewing for the National Sahti Competition. I had bought a packet of Finnish baker’s yeast, but when it was time to pitch yeast I began to hesitate. I had brewed a Norwegian farmhouse ale four days earlier, and a thick mat of kveik was still floating on the top of the brew. Why not just skim that yeast and ferment sahti with it, instead the same old baker’s yeast everybody else is using.
So I cropped the kveik from the maltøl and dumped it into sahti. Two days later I went to cellar to check if sahti had already fermented, and I instantly smelled vinegar and nail polish remover (ethyl acetate). It did not taste bad, but it had an obvious sour tang unacceptable for a traditional sahti or maltøl. I withdrew it from the competition.
I knew that this kveik I got from Hornindal includes souring bacteria, but I also knew that if used strictly according to the farmhouse brewing folklore, it will produce exquisite sweet ale which is not sour at all. What I could not believe is that this yeast could be distracted so easily from the path which it has been on for decades or even centuries.
Thus I learned the hard way that farmhouse yeasts are really delicate creatures. If one deviates from the traditional practices, things might take unexpected routes. That’s why farmhouse brewers are often reluctant to make any changes to the process.
Sometimes the hard way is the only way to learn. This accident gave valuable clues how kveik works, and I now have a pretty good idea what I should do differently next time. My long term plan is to learn using and maintaining kveik in a true farmhouse fashion, without any lab work. I will report this failure and the working practices eventually.
In the meantime, luckily I have lab purified yeast which produces premium beer. I just brewed a malty juniper ale from the branches shown in the header image. I hope that it will be a perfect autumn beer to drink while doing wobbly brewing experiments. In general juniper is an underrated beer ingredient in today’s home and craft brewing – not just berries but also the needles and wood.
Interesting! There’s definitely a reason why the farmhouse brewers harvest the kveik as early as they do.
Yes, it is really important to harvest kveik early and cool the ale soon after the vigorous fermentation. Four days was definitely too long. Luckily, I also harvested and dried kveik from the same batch of maltøl after two days, just to practice the drying technique. Now I can test how that yeast performs.