What is Buttermilk?
Buttermilk is tart milk created by the production of lactic acid during fermentation of lactose, the primary sugar within milk. The rise in acidity results in the tartness buttermilk is known for. During the production of lactic acid in fermentation the milk pH decreases leading the protein casein to precipitate causing the milk to curdle. Curdling is the reason behind the increased viscosity of buttermilk in comparison to traditional milk.
In baking, buttermilk is used in breads, biscuits, pancakes, and crackers to impart the distinct buttermilk flavor, add softness and moisture, as well as often used for leavening properties. For example in soda bread, buttermilk acidifies sodium bicarbonate to produce carbon dioxide enabling rise. Fried goods can be dipped in buttermilk before placed in frying oil to add taste as well as texture. Baked goods containing buttermilk can be identified by the rich flavor.
Use at less 10% liquid buttermilk (or <5% dry powdered buttermilk) to obtain the flavor without affecting the final pH.
FDA Legal Requirement