Yeast & Fermentation

How does a Dampfbier come about? The answer lies in the yeast. It's brewed top-fermented, meaning the yeast collects at the top of the fermentation vat's surface during fermentation. Top-fermenting yeast works at warmer temperatures—for Dampfbier, that's 18 to 20 degrees Celsius—and it works fast.

In the open wooden vats of the past, so much carbon dioxide formed that large gas bubbles rose to the surface and burst. It looked as though the beer were steaming. That's where the name comes from, and it has nothing to do with steam from a machine. Since 1989, the Zwiesel Dampfbier Brewery has, according to its own account, brewed its Zwiesel Dampfbier once again following the old recipe.

After primary fermentation, the brewery states that Dampfbier matures in the rock cellar just as it did in the past. There it's cold and damp, and the beer clarifies while the aromas meld together. How long it ages depends on the style. The brewery does not give consistent timeframes.

The region's Helles, by contrast, is bottom-fermented. Bottom-fermenting yeast works at cool temperatures, settles at the bottom at the end, and then lagers in the cold for weeks. This yeast is a hybrid of two species, descended from brewer's yeast and a wild yeast. Bavaria's brewers already relied on cool cellars in the Middle Ages, which is why bottom-fermentation became the everyday standard here.

In the forest, both worlds meet. Falter Private Brewery's wheat beer is top-fermented, as is the Dampfbier, while a Helles is bottom-fermented. Anyone wanting to compare can see at once from the foam and the aroma which yeast did the work. A visit to Felsenkeller Zwiesel makes this tangible.