What’s the difference between baking soda and baking powder? Are they interchangeable? I have always wondered why some recipes – even for the same thing like brownies or muffins – call for one and not the other.
Baking soda and baking powder are both leavening agents – they help baked goods rise. Baking soda is actually an ingredient in baking powder. They cannot be substituted for each other because chemically they are different, yet they both release carbon dioxide to help batter rise.
Baking soda is a leavener that requires an acidic ingredient in a batter to help a baked good rise. It is also know as sodium bicarbonate. In recipes using baking soda, you will commonly find an acidic ingredient like buttermilk, yogurt, chocolate or honey. Cookie recipes typically use baking soda.
Baking powder is a leavener that does not require an acidic ingredient in a batter to help a baked good rise. It is made from a combination of baking soda, cream of tartar and corn starch. The cream of tartar is an acid, so recipes that use baking powder don’t necessarily need to contain an acidic ingredient for the batter. The corn starch helps absorb any extra moisture and keeps the baking soda from acting too quickly. Cakes and biscuits are made with baking powder.
You can’t substitute anything for baking soda, but you can make your own baking powder — that is, if you have baking soda, cream of tartar and corn starch in your pantry. To make 1 teaspoon of baking powder, you need 1/4 teaspoon baking soda, 1/2 teaspoon cream of tartar and 1/4 teaspoon corn starch.