fermentation
n//ˌfɜː(ɹ)mənˈteɪʃən//jäsning, fermentering
(biochemistry) Any of many anaerobic biochemical reactions in which an enzyme (or several enzymes produced by a microorganism) catalyses the conversion of one substance into another; especially the conversion (using yeast) of sugars to alcohol or acetic acid with the evolution of carbon dioxide