Bottom-fermented
German: Untergärig
Fermentation with cold-loving yeasts at about 4 to 12 degrees Celsius that settle at the bottom; the basis of lagers.
In bottom fermentation, cold-loving yeasts (Saccharomyces pastorianus) work at about 4 to 12 degrees Celsius. After fermentation the yeast cells sink to the bottom of the vessel. The method only became possible once refrigeration was available and spread in the 19th century.
Slow fermentation and subsequent cold storage produce clean, clear beers with fewer esters. Pils, Helles, Märzen, Bock and dark lager are classically bottom-fermented. Most of the beer drunk in Germany is brewed this way. Maturation usually takes several weeks.