yeastgärning

Yeast fermentation is a metabolic process that converts sugar into alcohol and carbon dioxide in the absence of oxygen. This process is carried out by yeast, a single-celled fungus. The most common type of yeast used for fermentation is Saccharomyces cerevisiae, also known as brewer's or baker's yeast. When yeast encounters a sugar source, such as glucose or fructose, its enzymes break down these sugars into ethanol and carbon dioxide through a series of chemical reactions. This anaerobic respiration is distinct from aerobic respiration, which produces more energy but requires oxygen.

The process of yeast fermentation has been utilized by humans for thousands of years, primarily for the production of alcoholic beverages like beer, wine, and spirits, as well as for leavening bread. In brewing and winemaking, yeast is added to a sugary liquid (wort or must), and it ferments over a period of time, creating the alcohol content and characteristic flavors of the final product. For bread making, the carbon dioxide produced by the yeast causes the dough to rise, resulting in a lighter and airier texture. Different strains of yeast and varying fermentation conditions can significantly impact the final product's taste, aroma, and characteristics.