Baking Soda vs Baking Powder - What’s the Difference?


It’s a rare baking recipe that doesn’t use baking soda or baking powder. Chances are, you have a box of one or both of these in your pantry right now. But, you may not know what they are or what they do for your recipes. That’s about to change!

Keep reading to learn what these amazing products bring to the table and why. Plus, we’ll tell you how to test your baking soda and baking powder to see if it’s still usable and share a trick for when you’ve run out of baking powder.

Baking soda and baking powder do the same job, but differently.

Both ingredients are leaveners. To “leaven” something means to change it for the better - and baking soda and baking powder both do that! They’re added to baking recipes to provide lift. Without them, cakes, muffins, biscuits, etc., won’t rise up. Can you imagine a world of nothing but flat cupcakes? So, if they both make dough rise, what’s the difference?

What is baking soda?

Outside the kitchen, baking soda is called sodium bicarbonate. It’s naturally occurring but usually has to be processed out of minerals mined from the ground.

Baking soda is a base, so it’s the chemical opposite of an acid. (Anyone else trying to remember high school science class?) That means it needs an acidic element in the recipe to start a reaction and get the dough rising. Acids you might find in a recipe include yogurt, buttermilk, sour cream, cream of tartar, and brown sugar - our personal favourite.

If you keep your baking soda in a cool, dry place, it will last for a very long time, though the potency may gradually decrease. To test the strength of your baking soda, add ½ tsp to 1 tbsp of vinegar or lemon juice. If it’s still at full power, the mixture should start bubbling or fizzing right away. If it doesn’t, it may be in decline. In that case, you’ll either have to add more to compensate or buy new baking soda.

What is baking powder?

Now that you know baking soda is a base, you probably think baking powder is an acid. That’s a good guess, but it’s a bit more complicated than that.

Baking powder is a mixture of baking soda and an acidic component, usually cream of tartar. It also contains cornstarch to keep moisture from prematurely activating the reaction of the other ingredients. Since baking powder has its own acid trigger built in, it works in recipes that don’t have any acidic ingredients, like those we talked about in the baking soda section.

There are actually two kinds of baking powder: single-acting and double-acting. Most of what you’ll find at your grocery store is double-acting. It provides two separate reactions, one when you mix it with wet ingredients, and a second when heat is applied in the oven.

Like baking soda, baking powder should be kept in a cool, dry place. Unlike its counterpart, though, baking powder is only good for 6 to 12 months. To test your baking powder, add ½ tsp to ¼ cup of hot water. If it fizzes or bubbles right away, it’s ok to use!

What can I substitute for baking powder?

Let’s say you go to the cupboard and discover an empty space where you thought your baking powder was - now what? Well, since we know what’s inside, we can make our own!

To replace one tsp of baking powder in a pinch, mix ½ tsp of baking soda with ¼ tsp of cream of tartar and get baking!