What You Need to Know
During fermentation, lactic acid bacteria such as Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus convert lactose into lactic acid, lowering the pH to 4.5–5.0 and causing milk proteins to coagulate. The acidification also releases free amino acids and short‑chain fatty acids, enhancing flavor and digestibility. The process is driven by microbial metabolism and controlled by temperature, time, and microbial community balance.
The Science
Primary Reaction
Fermentation of lactose to lactic acid by lactic acid bacteria