Baking soda cannot be used as a direct one-to-one substitute for baking powder because they are chemically different with different leavening strengths and requirements. Baking soda is pure sodium bicarbonate and requires an acid in the recipe (like buttermilk, lemon juice, or vinegar) to activate its leavening properties. Baking powder, on the other hand, already contains both the base (baking soda) and an acid, so it only needs moisture to work. If substituting baking powder with baking soda, you need much less baking soda—about one-fourth the amount—and you must add an acidic ingredient to the recipe to trigger the leavening reaction. Using baking soda alone in place of baking powder without an acid will result in flat, dense, and possibly metallic-tasting baked goods. Conversely, if substituting baking soda for baking powder, you typically need about three times the amount of baking powder to baking soda to achieve the same leavening effect, but this can sometimes create a bitter taste if too much baking powder is used. In summary:
- Baking soda cannot simply replace baking powder without adding acid.
- For 1 teaspoon of baking powder, use ¼ teaspoon baking soda plus an acidic ingredient (e.g., ½ teaspoon cream of tartar or lemon juice).
- Using baking soda alone instead of baking powder will not work correctly in most recipes and may affect flavor and texture negatively.
