Buttermilk is fermented cow's milk with a distinctly sour taste.
Types of Buttermilk
- Traditional buttermilk: Leftover liquid after churning butter
- Cultured buttermilk: Lactic acid bacteria added
- Acidified buttermilk: Food-grade acid added
Buttermilk Substitutes
How Buttermilk Is Made
Buttermilk was once the leftover liquid from butter-making. It is quite different from modern buttermilk. Now buttermilk is generally produced by adding a bacterial culture to milk, similar to how yogurt or sour cream are made. The bacteria turn the lactose in the milk into lactic acid. If you add one part fresh buttermilk to four parts regular milk and leave the milk in a warm area, the regular milk should become buttermilk in a day or two.