Already known? The beer makes the difference

In the high art of brewing yeast plays an important role. It converts the malt sugar dissolved in the wort into carbonic acid and alcohol. Different yeasts are used. They determine the fermentation process. Roughly three varieties of yeast are distinguished - the top-fermented, the bottom-fermented yeasts and the spontaneous yeasts.

Top-fermented yeasts require temperatures of 15 to 20 degrees for malting sugar in alcohol. During the fermentation process, the yeast rises to the surface. There it forms coherent colonies and can be skimmed off. As long as there were no technical cooling methods, beers were produced almost everywhere in Germany with top-fermenting yeasts.

The differences in beer. Image: Givaga - fotolia

Bottom-fermented yeast needs temperatures between 4 and 9 degrees and sinks to the bottom of the kettle after fermentation. The fermentation process takes much longer than with top-fermented beer. For bottom-fermented beers are particularly enjoyable for a long time.

The top-fermented beers include Kölsch, Alt and Weißbier. Today, about 85 percent of all German beers are bottom-fermented - including pils, export or even bock beer.

Spontaneous beers play a relatively minor role in the market. They contain no yeast. Instead, yeast pores contained in the air stimulate the fermentation process in the open tub. This classic method is used by the first brewers when they did not know yeast. The most famous spontaneous beers are Kriek, Gueuze, Lambic or Jopenbier.

Until the invention of the chiller by Carl von Linde in the 1870s, bottom-fermented beer could only be brewed in winter. In regions with severe frost - in Bavaria and Württemberg - the beer brewers chopped ice from the waters in January and cooled the fermentation vats in deep cellars or caves. The supplies from the long winters lasted until the next cold season. While brewing was primarily brewing in these regions as early as the 16th century, the Rhinelanders, with their mild climate, developed particularly sophisticated top-fermenting techniques. Eva Neumann, aid