Emil Christian Hansen Introduces Pure Yeast Culture At Carlsberg

In November 1883, Carlsberg began using a pure culture of bottom-fermenting yeast developed by Emil Christian Hansen at the Carlsberg Laboratory in Copenhagen. Hansen had isolated a suitable yeast from a single cell and propagated it into a uniform culture, allowing the brewery to replace mixed pitching yeast that could contain wild yeasts responsible for inconsistent fermentation and beer spoilage. The first production-scale use of the culture demonstrated that lager could be fermented repeatedly with a selected yeast strain under controlled conditions. The yeast became known as Saccharomyces carlsbergensis, and Carlsberg made Hansen’s culture and method available to other breweries. Their spread transformed lager production by making fermentation more predictable, improving consistency, and establishing pure-culture yeast management as a central part of modern brewing science.