“Classical” Yeast Biotechnology

Abstract

Yeast was probably the first microorganism to be exploited by humans, and the brewing of alcoholic beverages and the leavening of bread using yeast represent the oldest, and still the largest, biotechnologies. The earliest records of the use of yeast date to before 6000 B.C. when the Sumerians and Babylonians exploited the organism, albeit unconsciously, in the production of beer (Corran, 1975). The use of yeast to leaven bread by the production of carbon dioxide was developed at a much later date, in Egypt at ca. 4000 b.c. The ancient Egyptians extended their bread-making technology to the production of an acidic beer called boza or boozah from a lightly baked “loaf” of germinated grain. The production of distilled liquor probably originated in either China or the Middle East and was common throughout the known world by the 14th century a.d