What You Need to Know
During fermentation, lactic acid bacteria such as Lactobacillus kefiranofaciens reduce lactose to lactic acid, while acetic acid bacteria oxidize lactate to acetic acid. Yeasts metabolize sugars to produce CO₂ and trace alcohols, contributing to the beverage’s effervescence. The microbial consortium also synthesizes kefiran, a polysaccharide that imparts viscosity and stabilizes the grains.
The Science
Primary Reaction
Lactose → lactic acid + acetic acid + CO₂ + ethanol (via microbial consortium)