Wiki Defines Fermentation as a metabolic process that converts sugar to acids,
gases and/or alcohol. It occurs in yeast and bacteria, but also in oxygen-starved muscle cells, as in the case of
lactic acid fermentation. Fermentation is also used more broadly to refer to the bulk growth of microorganisms
on a growth medium. French microbiologist Louis Pasteur is often remembered for his insights into
fermentation and its microbial causes.
The science of fermentation is known as zymology.