Baking soda, or sodium bicarbonate, is a leavening agent used in baking recipes. Baking soda, unlike baking powder, is added to recipes with an acidic liquid. Although baking soda is not easily substituted, there are a few things you can do in an emergency if you're out of the substance.
Classification
Baking soda reacts by releasing carbon dioxide bubbles when mixed with acidic liquids. The released bubbles help baked goods rise and make the batter light and spongy. Some recipes call for both baking soda and baking powder to help offset acidity. Although you can leave out the baking soda in these recipes, the taste and color of the finished product will be somewhat affected.
Baking Powder
You may be able to use baking powder as a baking soda substitution in an emergency, depending on your recipe. For every ½ teaspoon of baking soda, you can substitute 2 tablespoons of double-acting baking powder. You will need to replace any acidic liquids in your recipe with non-acidic liquids, if possible. Generally, when a recipe calls for baking soda, it is because there is an acid in the mixture that needs to be released.
Potassium Bicarbonate
Potassium bicarbonate, or potash, is used as a natural pesticide, in making soaps, and in brewing your own beer. It is an odorless substance that can be used to replace baking soda. When using this leavening agent to replace baking soda, use the same measurements of potassium bicarbonate to replace the baking soda. Look for the product in the home and garden section of a department store, at a natural health store, or a brewery supply store.
Baker's Ammonia
Baker's ammonia, or hartshorn, is a leavening agent in many older recipes. It's okay for use in thin, porous baked goods like cookies, but not in large items like cakes. Depending on the recipe, hartshorn usually substitutes for baking soda in equal amounts. Although a strong odor of ammonia exists while cooking, the odor will disperse after cooking. Baker's ammonia may be preferable to baking soda because it does not leave an unpleasant alkaline aftertaste. Look for it in grocery stores or a European specialty market.
