Is Baking Soda the Same as Baking Powder (and Can You Substitute One for the Other)?

Baking soda has always been a household staple: This handy powder can help you spruce up your oven, dishwasher and even UGG boots, leaving them all looking as good as new. However, when it comes to whipping up a delicious treat, baking soda can often be confused with fellow leavening agent, baking powder. So, is baking soda the same as baking powder? Find out how they differ below (and what to do if you need one but only have the other). 

According to baking soda manufacturer Arm and Hammer, this household staple is made of pure sodium bicarbonate. Baking soda—which is also known as bicarbonate of soda—is a quick-acting leavening agent that reacts as soon as it’s mixed with moisture and acidic substances such as buttermilk, honey, brown sugar or vinegar (the latter is particularly useful in cleaning applications). That little spurt of bubbles that appears when you mix baking soda with liquid is what gives your dough or batter the light, fluffy texture that makes Paul Hollywood swoon. And because baking soda is fast-acting, you want to make sure to pop your dough or batter into the oven before those bubbles dwindle down. 

Baking powder, on the other hand, is a combination of baking soda, acidic salts or dry acids such as cream of tartar and some form of starch (most commonly cornstarch). Because baking powder contains both the sodium bicarbonate and acid needed for your dough or batter to rise, it’s typically used in baking recipes that don’t require additional acidic substances such as buttermilk or molasses. Think: sugar cookies or brownie pops.

There are two types of baking powder—single-action and double-action. Single-action baking powder is similar to baking soda in that it creates carbon dioxide bubbles as soon as it’s mixed with moisture, so you need to get your dough or batter into the oven swiftly.

In comparison, double-action has two leavening periods: The first reaction happens when you mix your dry and wet ingredients to make dough. The second happens once the dough reaches a specific temperature in the oven. Double-action is the most commonly used of the two and probably what's sitting in your cupboard right now. However, if you stumble upon a recipe asking for single-action baking powder, you can easily substitute with double-action without adjusting the measurements, our friends at Bakerpedia tell us.   

The simple answer is yes. However, there are several caveats you have to consider. Swapping these two ingredients can be disastrous, but it is possible—as long as you’re precise with your measurements. Because their chemical composition is different, substituting is not a direct one-to-one conversion.

If your recipe asks for baking soda but you only have baking powder, the pros at Masterclass strongly suggest you remember the former is a stronger leavening agent, so you’ll need about three times the amount of baking powder as you would baking soda. For example, if a recipe calls for one teaspoon of baking soda, try substituting with three teaspoons of baking powder. The downside to this is that if the measurements are off, you’ll have a very bitter pastry on your hands.

On the flip side, if you’re trying to replace baking powder with baking soda, not only do you have to remember to put less baking soda than you would powder, but you also have to keep in mind that you must add an acid to the recipe—buttermilk, honey, etc. Failure to do so will result in metallic-tasting, dense and hard baked goods. Arm and Hammer recommends that for every teaspoon of baking powder you use ¼ baking soda instead, plus ½ teaspoon of cream of tartar. No cream of tartar? No problem. Here are six more substitutes for baking powder that are just as good as the real thing.

Whether you’re planning on baking a boatload of sugar cookies using baking powder or you have a decadent cinnamon sheet cake with cider frosting in mind, don’t forget to check if your leavening agent of choice has expired before you begin baking. The two tend to have a relatively long shelf life, so it’s easy to bypass the expiration date.

If you can't find the expiration date, you can test if your baking soda is still good by pouring three tablespoons of white vinegar into a small bowl and adding ½ a teaspoon of baking soda. If the mixture reacts, you’re good to go. If it doesn’t, it’s time to restock. Use the same method but replace vinegar with water to test your baking powder.