Baking powder is a common leavening agent made from a combination of an acid, typically cream of tartar, which is the potassium salt of tartaric acid, and a base, which in this case is baking soda.

When To Use Baking Soda Versus Baking Powder Baking soda is a base, meaning you'll have to manually add in an acid for it to react. Acids have hydrogen ions and a pH lower than seven.

Baking soda can also release carbon dioxide gas when it is heated at temperatures above 80°C. When you mix baking soda into a cake batter, you will see some initial chemical activation by food acids.