What is "buttermilk"?

Buttermilk is a tangy and acidic dairy product that is made by fermenting milk with lactic acid bacteria. Traditionally, buttermilk was the liquid that remained after churning butter from cream. However, modern buttermilk is often made by adding lactic acid bacteria to low-fat or skim milk. The fermentation process gives buttermilk its characteristic tangy taste and thick, creamy texture. Buttermilk is a versatile ingredient that is used in a variety of recipes, including baked goods, marinades, and dressings. It is particularly popular in Southern cuisine, where it is used as a tenderizing agent for fried chicken and other dishes. Buttermilk is also a good source of calcium, vitamin D, and protein, and is often consumed as a part of a healthy diet.