lactobacili

The lactobacili in the milk eat lactose and turn it into lactic acid.

Especially in a warm environment the lactobacili in the milk itself and in the air will do their job and you'll have curdled milk in the morning.

Cheesemaking begins with a fermentation step where lactobacili and lactococci are used to increase the acidity of milk to speed up its coagulation by rennet enzymes in a subsequent step.

Lactobacili that curdle the milk naturally actually release lactic acid: fermentation is the same kind of anaerobic respiration that happens in our muscles when they're not getting enough energy from oxygen alone.

Lactobacili that curdle the milk naturally actually release lactic acid: fermentation is the same kind of anaerobic respiration that happens in our muscles when they're not getting enough energy from oxygen alone.