What are the reactants and products of fermentation?

The fermentation reaction is a biochemical reaction which involves a microorganism consuming a substrate (Carbon - source) and in order to produce several products such as alcohol, proteins, amino acids, biogas etc.

The most common reactant/substrate for a fermentation reaction is sugar, specifically glucose and the most common product is alcohol. If the fermentation process is aerobic in nature, then a oxygen is also required as reactant. By products include carbon dioxide, sulfur oxides etc.