Yeast & Fermentation

Helles, Export and Doppelbock here all ferment bottom-fermented, meaning: the yeast works at low temperatures and settles to the bottom at the end. The result is a clean, quiet aroma without the fruity esters top-fermenting yeasts produce.

Fermentation is followed by lagering. The beer rests for weeks in cold tanks or cellars, where it clears and rounds out. For Starkbier, this takes considerably longer, since alcohol and malt fullness need time to come together.

Then there's Weissbier. Ayinger's Bräu-Weisse is top-fermented and, with its clove and banana notes, recalls a classic Hefeweizen. Here fermentation runs warmer and fruitier than with a Helles.

The historic trick of the Tölz brewers was cooling, not yeast. In the tuff cellars, the beer lagered cold until it went to Munich by raft in summer. Today, cooling systems do this work, but the idea behind it hasn't changed: ferment cold, mature cold.

Why does Helles taste so smooth? Because cold fermentation produces few byproduct flavors, and long lagering breaks down the rough edges young beer still carries. Brewers call this maturing. Part of the process is also separating the yeast at the end, or letting it settle in the tank, so the beer pours bright into the glass. Order a cloudy, unfiltered Kellerbier instead, and you'll get the yeast still in your glass, tasting a bit breadier and softer, though not necessarily more intense. That's a matter of habit and taste.