Baking powder, baking soda, and cream of tartar are all leavening agents, meaning they are used to help baked goods rise. However, each one works differently and has different uses in baking.
Baking powder is a combination of baking soda, an acid (such as cream of tartar), and a moisture-absorbing substance (such as cornstarch). When baking powder is mixed with liquid, the acid and baking soda react to produce carbon dioxide gas, which causes the dough or batter to rise. Baking powder is often used in recipes that do not have an acidic ingredient, as the acid in the baking powder helps to balance the pH of the recipe.
Baking soda, also known as sodium bicarbonate, is a pure form of alkaline leavening agent. It reacts with acids to produce carbon dioxide gas, which causes dough or batter to rise. Baking soda is often used in recipes that contain an acidic ingredient, such as buttermilk, yogurt, or lemon juice.
Cream of tartar, also known as potassium bitartrate, is an acidic powder that is a byproduct of wine production. It is often used in conjunction with baking soda to help stabilize and provide a more consistent rise in baked goods. Cream of tartar is also used in meringues to help stabilize the egg whites and prevent them from collapsing.
In summary, baking powder is a pre-mixed combination of baking soda and an acid, while baking soda and cream of tartar are used separately in recipes that contain an acidic ingredient. It is important to use the correct leavening agent in a recipe to ensure proper rising and flavor balance.