Yeast & Fermentation

How does wort become beer? Yeast consumes the sugar and turns it into alcohol and carbon dioxide. Two types are at work in this region: Bockbier and Helles ferment bottom-fermenting, at cool temperatures, while the Weissbiers ferment top-fermenting, warmer and faster.

Top-fermenting yeast collects at the surface after fermentation, while bottom-fermenting yeast sinks to the bottom. Weissbier yeast produces aromas you recognize instantly — banana and clove, for instance. That's why a Weissbier from Maisel's or Kapuziner tastes completely different from a Bock from the same stretch of land, even though both contain wheat or barley.

According to Kulmbacher Brauerei AG, its breweries work with their own cultivated yeast strains. Such cultivation keeps the strain clean and consistent, which matters for a strong beer, since yeast struggles with high sugar content. The stronger the wort, the longer fermentation takes. EKU 28, a strong beer from Kulmbacher Brauerei, likewise demands patience during fermentation and lagering because of its powerful wort.

Eisbock requires an extra step. The fully lagered Bockbier is chilled down far enough that part of the water freezes. The ice is removed, leaving behind a beer that's denser and stronger than before. Experts call this freeze concentration, and for Kulmbacher Eisbock, it's part of the beer's tradition.

How long a Bock lagers is up to each individual brewery. As a rule of thumb, strong beers age longer than weak ones, often for weeks to months, so the flavors can round out. Weissbier, by contrast, goes into bottle or cask quickly, since its freshness is central to its character.