Pitch temperatures in traditional farmhouse brewing
Historically, farmhouse brewers brewed beer from their own grain all over northern Europe, using yeast they maintained in the local community. A large proportion of them, perhaps around 60%, fermented at temperatures close to body temperature, according to a survey of 287 independent accounts of farmhouse brewing practices in 10 different countries. Recent genetic studies indicate that this was possible because the yeasts used in farmhouse brewing, although domesticated, were different from those used in modern brewing. Since wild yeast appears to have high temperature tolerance and modern commercial brewing arose out of earlier farmhouse brewing practices, it seems that the lack of high temperature tolerance in modern brewer’s yeast may be due to a loss of function as the yeast adapted to commercial brewing practices.