Baking Powder and baking soda are both chemical leavening agents. Much like yeast helps bread rise by fermentation, these leaveners give cakes, cookies, and other baked goods lift and airiness. Unlike yeast, they don’t contribute any flavor to the final product.
When added to dough or batter, chemical leaveners trigger the release of carbon dioxide gas, creating hundreds of little air bubbles that yield light and fluffy baked goods. “Both baking soda and Baking Powder produce carbon dioxide through an acid-base reaction,” writes Epi contributor Mari Uyehara in her deep dive on baking soda. But that’s where the similarities end.
Baking soda is a base, with an alkaline pH of 8.5. To produce carbon dioxide, it needs to react with an acid. That acid can come from any number of places. “In early days, that often meant sour milk,” Uyehara notes; today, bakers often rely on acidic ingredients like buttermilk, yogurt, white vinegar, brown sugar, and chocolate to link up with baking soda and create a chemical reaction. Once combined with an acid, baking soda works quickly to produce carbon dioxide and give your batter a boost.
An equal volume of Baking Powder has about a quarter of the strength of baking soda, making its reactions much slower and easier to control. So you can’t interchange Baking Powder for baking soda or vice versa.
