Why is a starter added to the milk into curd? Explain? (2024)

Pasteurized milk is heated to a temperature of 30-400C, or even at room temperature or refrigerator temperature, and a small amount of old curd or whey added to it, the lactobacillus in that curd or whey sample starts to grow. These convert the lactose into lactic acid, which imparts the sour taste to curd. When a small amount of starter is added to milk, it gets converted to curd. The curd when added into the milk, the Lactic acid bacteria present in the curd cause coagulation of casein which convert into curd. Curds are a dairy product obtained by curdling (coagulating) milk. The coagulation can be caused by adding rennet or any edible acidic substance such as lemon juice or vinegar, and then allowing it to set. The increased acidity causes the milk proteins (casein) to tangle into solid masses, or curds. Milk that has been left to sour (raw milk alone or pasteurized milk with added lactic acid bacteria) will also naturally produce curds and sour milk cheeses are produced this way.