Flavor – Why does the sour taste in yogurt increase with time

fermentationflavoryogurt

If we let yogurt sit for more days, the yogurt becomes more and more sour. Why does that happen?

Best Answer

Lactic acid is produced by 'probiotic' bacteria breaking lactose into lactic acid. Over time, more lactose is converted, producing more byproducts, thus more sourness.

The byproducts of this reaction are responsible for the distinctive flavor of yogurt.

See a more complete description here: Lactic Acid Fermentation