Yeast is a single-celled micro-organism that belongs to the family of minute fungi that multiply in sugar solutions, such as malted barley. Yeast is essential for the production of beer. The nitrogen components of the sugars are metabolized by the enzymes produced by the yeast during fermentation, forming, among other things, alcohol. There are many kinds of yeast, and most breweries jealously guard their own culture yeast, which shapes the specific taste of their beer. Particular attention is paid to quality and hygiene during the production process to ensure that beer does not cause any direct risk for health. Quite the contrary, brewer’s yeast is often praised for its beneficial effects on health. There are no alternatives to the use of yeast in beer production.