Does Baking Powder Go Bad?

Unless you’re a big-time baker, an opened container of baking powder probably sits in your kitchen cabinet for quite some time. That time can be months, or sometimes even years if you only use this leavening agent from time to time. At some point, the question “does baking powder go bad?” comes up.

Since this baking ingredient is just powder, you may think that it lasts pretty much indefinitely. I mean, if water doesn’t get to it, what bad can happen?

Baking Powder
(credit: Mel B. )

Unfortunately, that’s not entirely true. While the powder will remain safe to use pretty much forever, it won’t do its job as a leavening agent forever. In other words, at some point, you might add it to your baked goods, and they won’t rise as they should. Or at all. When that happens, it means that your baking powder lost its potency.

If you’d like to learn more about storing, shelf life, spoilage, and potency of baking powder, read on.

How To Store Baking Powder

You should store baking powder the same way you store other powdered products, such as wheat flour, baking soda, or cream of tartar. That means you should keep the package in a cool and dry place. The pantry or a cupboard in the kitchen will work just fine for that.As with pretty much all powders, you want to store them away from any sources of moisture.

Once you open the package, keep it sealed tightly. As you can see, no rocket science here.

How Long Does Baking Powder Last

Most packages and containers of baking powder come with a “best-by” date. That date informs you of how long, at the very least, the product retains its quality. For baking powder, it’s just a rough estimate. So you can easily assume that an unopened package of baking powder will work as it should after that date.

How long exactly? It’s difficult to tell. I’d suggest that if you open a package of baking powder that’s more than three months past the best-by date, you should check its potency before using. This way, you will know if the powder still works or not.

Baking powder ready for proofing

Once you open the package, most sources suggest you should use it within half a year. In short, once air gets to the container, the powder starts to lose its potency a bit quicker, hence the 6-month recommendation.


If your baking powder is opened for longer than those six months, always check its potency before using it in a baking project.

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

Please note that the periods above are just rough estimates. If you store baking powder for a long time, check its potency before using it.

How To Tell If Baking Powder Has Lost Its Potency Or Is Bad

As I’ve mentioned earlier, baking powder doesn’t go bad in a way it’s unsafe to eat, unless some water or other substances will reach it. Unfortunately, there aren’t any visible signs that tell us that the powder is still potent. Fortunately enough, there is a way to check if our baking powder will do its job.

Take a third of a cup of hot water and add one teaspoon of baking powder to it. If the prepared mixture bubbles, baking powder is good enough to be used. It should look like that:

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 safer to discard it. Baking powder is pretty cheap, and it’s less expensive to buy a new package of baking powder than to throw out a ruined cake.

Of course, if there’s something wrong with the powder, like there’s mold or any other growth in the package, you should discard it. That most likely means moisture found a way to get to the container.