What You Need to Know
During fermentation, lactose is converted by homofermentative lactic acid bacteria into lactic acid, lowering the pH and causing casein coagulation. Heterofermentative cultures also produce CO₂ and ethanol, contributing to gas formation and flavor complexity. Proteolytic enzymes from the cultures cleave casein into peptides, while lipolytic activity releases free fatty acids that further develop the characteristic taste of aged cheeses.
The Science
Primary Reaction
Lactose → 2 lactic acid (homofermentative) or lactic acid + CO₂ + ethanol (heterofermentative)