Question: what is the difference between buttermilk and sour milk?
Answer: Many people think sour milk and buttermilk are the same but they are different. Buttermilk used to be the watery stuff leftover from making butter. These days, it is made by adding a lactic acid bacteria to regular pasteurized milk. Sour milk is made by adding vinegar and lemon juice to regular milk to make it sour.