Sour Milk

Baking powder can be replaced by sour milk. In the past, people used milk that had spoiled. However, you may make your own sour milk at home by mixing 1 cup of milk with 1 tablespoon of white vinegar or lemon juice. The pH will be lowered by the vinegar or lemon juice, making the milk sour. It will be prepared for use in a little more than 15 minutes.

The acidification process that soured milk results in a drop in pH. Baking soda and sour milk combine to produce the same leavening result as baking powder. To substitute 1 teaspoon (5 grams) of baking powder, use 1/2 cup (122 grams) of sour milk and 1/4 teaspoon (1 gram) of baking soda. To account for the additional liquid from the sour milk, don't forget to decrease the amount of liquid in your recipe by the same amount that was added.