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

The primary difference between baking powder and baking soda lies in their composition and how they are activated. Baking powder is a complete leavening agent that contains sodium bicarbonate along with an acid, which is often in the form of cream of tartar or other acidic compounds. This means that when it is combined with moisture, a chemical reaction occurs, producing carbon dioxide gas that helps baked goods rise.

Baking soda, on the other hand, is purely sodium bicarbonate and requires an acid (such as vinegar, lemon juice, or yogurt) in the recipe to activate it and produce carbon dioxide. Therefore, the activation of baking powder by moisture while containing its own acid distinguishes it from baking soda.

This fundamental difference is pivotal for understanding why certain recipes call for one or the other, as using the incorrect leavening agent can significantly affect the texture and rise of the final product. Understanding the roles of these ingredients is essential for successful baking.