Does Baking Powder Go Bad?

Baking powder is essential to many baking recipes, helping to ensure that your baked goods rise and get light and airy. But it's also not something you may be using in everyday cooking, so that canister of baking powder could be sitting on your shelf for a long time. The big question is: Can baking powder go bad? And the short answer: Yes! (But not in the same way that perishables like eggs and milk can.)

Here's everything you need to know about how long that baking powder stays good, how to tell if your baking powder has gone bad, and what you can do to keep your baking powder fresh longer.

When Does Baking Powder Expire?

In general, baking powder and baking soda share similar shelf lives, as baking powder is essentially baking soda with acid and thickener added in (generally, cream of tartar and corn starch). That's why you can't use baking soda to fill in for baking powder—unless you add some of those ingredients as well.

Because baking powder and baking soda have a similar makeup, baking powder will last about six months on the shelf once it's opened, and three years in an unopened package.

How to Tell When Baking Powder Goes Bad

Baking powder won't have an off smell or taste—unless it's been contaminated with something else. And it is safe to use past its expiration date, even if it isn't as effective. You'll just end up with a flatter, denser baked good than you would if you used fresh baking powder.

If you've found some baking powder in the back of your pantry and aren't sure if it's effective, there's an easy way to tell: Just add some baking powder to hot water. If it seems to fizz and react, your baking powder should work just fine in your recipe.

How to Store Baking Powder to Extend the Shelf Life

Air, light, heat, and humidity aren't baking powder's friends, and they can all contribute to making your baking powder expire faster. Store your baking powder in an airtight container in a cool, dry place to help it maintain its potency.

How to Use Up Your Baking Powder

If you're not a regular biscuit baker, soda bread, or other baked goods that call for baking powder, you may find yourself with baking powder on the verge of expiration.

The good news: You can use baking powder to clean just as you'd use baking soda. Just keep in mind that because baking powder has both acid (from the cream of tartar) and base (from the baking soda), it may not be quite as powerful at cleaning big messes. But baking powder can still serve as a gentle scrub for countertops and grout, a deodorizer for stinky shoes, refrigerators, or mattresses, and other similar cleaning tasks.