Fermentation is a bio-chemical reaction. Yeast cells participate on biological activity, while sugar (C12H22O11) is involved in the fermentation process used for the manufacturing of alcohol. Overall fermentation process is very complex. Fermentation is divided into following steps. In principle, glucose molecules are consumed by yeast cells and in turn they excrete ethanol molecules and liberate carbon dioxide. This is an exothermic reaction, Following equation represents the fermentation reaction:

yeast C6H12O6 = 2 C2H5OH + 2 CO2 + Heat

Living yeast cell generates an enzyme, called as invertase enzyme, at the cell wall surface. These enzymes hydrolyze one sugar molecule (disaccharide) into two mono-saccharide molecules, called as glucose and fructose. This mono-saccharide is involved in conversion to alcohol.

Following equation represents the hydrolysis of sugar to glucose & fructose at cell surface

C12H22O11 + H2O = C6H12O6 + C6H12O6

(Disaccharides) Invertase Inzyme (Monosaccharide)