GENERAL KNOWLEDGE

Detailed explanation-1: -Curd taste sour due to lactic acid. When the consistency is attained, the curd should be refrigerated to stop it from further fermentation. If the temperature is not lowered then the population of bacteria might increase producing more lactic acid resulting in bitter taste.

Detailed explanation-2: -Sourness is mainly caused by the detection of protons. Numerous organic and mineral acids, such as citric acid, malic acid, tartaric acid, lactic acid, acetic acid, hydrochloride acid, are responsible for sourness.

Detailed explanation-3: -Lactic acid is present in curd. Q. Q. Curd is sour in taste due to the presence of acidic substance.

Detailed explanation-4: -This rapid increase in bacteria, in turn, increases the production of lactic acid in yogurt. This is what eventually causes the curd to taste sour.