Does Baking Powder Go Bad? [And How to Tell if It’s Still Good]

Here’s all you need to know about the shelf life and expiration of baking powder. Learn how long baking powder lasts and how to test if it’s still okay to use.

Unless you’re a big-time baker, an opened container of baking powder might sit in your kitchen cabinet for quite some time. And after a couple of months, you start wondering: does baking powder go bad?

Or maybe you found an old packet that’s expired for a few months, and you’re wondering if there’s a way to test if it’s still any good.

Sounds familiar?

If so, this article is for you. Let’s jump right in.

Baking Powder
(credit: Mel B. )

Does Baking Powder Go Bad?

Baking powder stays safe to use pretty much indefinitely, but it doesn’t retain freshness forever. It gradually loses potency, and at some point after the printed date, you’ll notice that your baked goods don’t rise as well as they used to. Or at all.

Fortunately, if your baking powder is already “expired” or stored for more than a few months after opening, you’re not left with either tossing it or using it in a baking project and hoping for the best. Instead, there’s a simple way to tell if your baking powder still works as a leavening agent.

Let’s talk about that.

How to Tell if Baking Powder Is Still Good?

To test if your baking powder is still good, grab a cup and add one teaspoon of baking powder into it. Then, pour 1/3 cup of hot water into that cup.

If the mixture is bubbling heavily, your baking powder is still potent. However, if there are only some bubbles here and there, your baking powder is losing its potency, and it won’t be good enough to leaven your baked goods.

Here’s what you’re looking for:

Baking powder bubbling
Baking powder bubbling

No bubbles mean it has lost its potency, and you can discard it.


If you’ve got only a teaspoon of baking powder left, and it’s already sitting in storage for a long time, it’s safer to discard it. Baking powder is pretty cheap, and it’s cheaper to buy a new package than to throw out a ruined cake.

Gingerbread cake with jam and sprinkles
Your cake won’t rise properly if the baking powder you used is not fresh

Alternatively, if you’re making pancakes, you can test your baking powder by preparing your pancake batter the usual way, and cooking one small pancake using it. If the pancake is nice and fluffy, your baking powder is fresh. If it’s flat and dense, the powder is gone, and you have to stir in some fresh baking powder to fix the issue.

I suggest the same approach in my article on the shelf life of pancake mix.

(This sort of trial-by-combat approach works only for a handful of dishes, where you can cook a small batch to test the waters. You don’t want to go that route when baking a cake, for instance.)

Of course, if there’s something wrong with your baking powder, like there’s mold, wet clumps, or pantry bugs got inside the container or bag, you should discard it.

Muffins with mango puree
The air pockets in muffins are the result of baking powder reacting to heat.

How Long Does Baking Powder Last?

Baking powder (unopened)Best by + 6 months
Baking powder (opened)3 – 6 months

Unopened baking powder lasts for a few months beyond the printed date before it loses potency. After opening the package, it retains freshness for about 6 months.

If your baking powder is “expired” or opened for more than a couple of months, test its potency using the instructions outlined above before using it in baking. This way, you don’t end up with dense muffins or a flat cake.

Baking powder has a long shelf life of about 18 to 24 months from the day it’s packaged. And it’s not like it loses its potency a few days after the printed date. But it’s also not like it will last forever.

After Expiration Date

Unopened baking powder should stay fresh for a couple of months beyond the date on the label, but it’s impossible to tell exactly how long.

So if you want to use your “expired” baking powder for baking, check its freshness using the method described above before using it.

That takes only a minute or two but prevents you from using a baking powder that doesn’t do its job. In other words, it’s definitely worth the time investment.

Baking powder ready for proofing
Prep for checking the potency of my baking powder

After Opening

Baking powder should retain freshness for about 6 months after opening the package. Once air gets to the powder, it loses its potency more quickly, hence the 6-month recommendation.

So if you want to use your baking powder that’s been opened for who knows how long, check its potency before using it for baking. This way, you won’t end up with dense cupcakes or a flat cake.

How To Store Baking Powder

Store your baking powder in a cool and dry place, away from heat sources. The pantry or a cupboard in the kitchen will work just fine , as long as you don’t place the package directly above the stove.

Once you open the package, keep it sealed tightly. If the original bag isn’t resealable, transfer the powder to a freezer bag or airtight container, or seal it using a plastic sealing clip.

If it’s a small packet you’ll use within a few weeks tops, just rolling the top is usually enough. That’s what I do.

As you can see, no rocket science here. You store baking powder the same way you store other powdered products, such as wheat flourbaking soda, or cream of tartar.

Freshly baked raspberry muffins
Freshly baked raspberry muffins. They rise thanks to the baking powder.

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