What is the main difference between baking powder and baking soda?

The main distinction between baking powder and baking soda lies in their chemical composition and how they are activated in baking processes. Baking powder contains both an acid and a base, along with a moisture-absorbing ingredient that ensures it remains stable until mixed into a batter or dough. When baking powder is combined with moisture and heat during cooking, it produces carbon dioxide gas, which helps the baked goods rise.

On the other hand, baking soda is purely a base (sodium bicarbonate) and does not contain any acid. It requires an acid to be added to the recipe, such as vinegar or buttermilk, to activate it and produce the necessary carbon dioxide for leavening. This fundamental difference in composition and activation is essential for achieving the desired textures and risen qualities in various baked items.

Understanding this difference is crucial for successful baking, as using the correct leavening agent can significantly impact the outcome of a recipe. For instance, recipes requiring baking soda often have an acidic component, while baking powder is typically used when a separate acid is not included.