Science, Tech, Math › Science The Difference Between Baking Soda and Baking Powder Breaking Down Their Chemical Composition Share Flipboard Email Print ThoughtCo / Nusha Ashjaee Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated January 24, 2020 Both baking soda and baking powder are leavening agents, which means they are added to baked goods before cooking to produce carbon dioxide and cause them to rise. Baking powder contains baking soda, but the two substances are used under different conditions. Did You Know? You can substitute baking powder in place of baking soda (you'll need more baking powder and it may affect the taste), but you can't use baking soda when a recipe calls for baking powder. Baking Soda Baking soda is pure sodium bicarbonate. When baking soda is combined with moisture and an acidic ingredient—such as yogurt, chocolate, buttermilk, or honey—the resulting chemical reaction produces bubbles of carbon dioxide that expand under oven temperatures, causing baked goods to expand or rise. The reaction begins immediately upon mixing the ingredients, so you need to bake recipes that call for baking soda immediately, or else they will fall flat. Baking Powder Baking powder contains sodium bicarbonate, but it already includes the acidifying agent (cream of tartar) as well as a drying agent, usually starch. Baking powder is available as a single- or double-acting powder. Single-acting powders are activated by moisture, so you must bake recipes that include this product immediately after mixing. Double-acting powders react in two phases and can stand for a while before baking. With double-acting powder, some gas is released at room temperature when the powder is added to the dough, but the majority of the gas is released after the temperature of the dough increases in the oven. How Are Recipes Determined? Some recipes call for baking soda, while others call for baking powder. Which ingredient is used depends on the other ingredients in the recipe. The ultimate goal is to produce a tasty product with a pleasing texture. Baking soda is basic and will yield a bitter taste unless countered by the acidity of another ingredient, such as buttermilk. You'll find baking soda in cookie recipes. Baking powder contains both an acid and a base and has an overall neutral effect in terms of taste. Recipes that call for baking powder often call for other neutral-tasting ingredients, such as milk. Baking powder is a common ingredient in cakes and biscuits. Substituting in Recipes You can substitute baking powder for baking soda (you'll need more baking powder and it may affect the taste), but you can't use baking soda when a recipe calls for baking powder. Baking soda by itself lacks the acidity to make a cake rise. However, you can make your own baking powder if you have baking soda and cream of tartar. Simply mix two parts cream of tartar with one part baking soda. Related Reading Six Simple Buttermilk Substitutes: Most buttermilk you buy is made using chemistry. You can make homemade buttermilk by adding an acidic kitchen ingredient to milk.Common Ingredient Substitutions: Baking powder and baking soda aren't the only cooking ingredients people run out of.How Baking Powder Works: Learn how baking soda makes baked goods rise and why it's used in some recipes but not others.How Baking Soda Works: Learn how baking soda works and how this affects how quickly you need to bake a recipe once you mix it.Baking Powder Shelf Life: Baking powder doesn't last forever. Learn about its shelf life and how to test it for freshness so your recipe doesn't fall flat.