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Does Cake Mix Go Bad? Can You Use It After It’s Expired?

Let’s talk about the shelf life and expiration of cake mix.

Say your half-open cake mix has been open for a couple of months, and you’re wondering if it’s still any good. Does cake mix ever go bad or expire?

Or maybe yours is already a few months past the printed date but looks perfectly fine. That makes you wonder: can you use an expired cake mix?

If either sounds familiar, you’re in the right place. Read on.

Cake mix bag
Cake mix bag

Table of Contents

Does Cake Mix Go Bad or Expire?

Cake mix, if stored in a cool and dry place, doesn’t go bad in the traditional meaning of the word. It doesn’t grow mold, start to smell off, or lose flavor. But if stored long enough, it will lose some or all of its potency, and any cake you try to use it in won’t rise properly.

A cake mix is basically a mix of sugar, flour, salt, and a leavening agent. And as you probably know, flour, sugar, and salt all have a long shelf life.

The only ingredient from the four that doesn’t last years is the leavening agent, such as baking powder. The same is true for any other leavening agent, such as baking soda, for that matter.

Baking powder (or soda) gradually loses potency and, if stored long enough, will lose all of its leavening power. If that happens, any cake you use it in will end up flat and dense instead of fluffy and airy.

Which is far from what you’d want from a cake, of course.

That brings us to the next question.

Oat milk and spinach cake
Oat milk and spinach cake

Can You Use Expired Cake Mix?

Yes, you can use an expired cake mix, as long as you add some extra baking powder to make up for the lost potency. Without it, anything you bake won’t rise properly and will end up a flat and chewy disappointment of a cake.

(We’ll discuss how much baking powder you should add in the next section.)

The idea here is pretty simple.

The flour, salt, sugar, and other ingredients (besides the leavening agent) that your cake mix might include are likely perfectly fine for months, if not years, beyond the printed date.

The only ingredient that loses some or all of its potency is the rising agent. And as you know, baked goods don’t rise properly without it. So we have to mix in something to make up for that, and baking powder is the easiest one to use, as it doesn’t need any extra acid to activate.

Unfortunately, there’s no good way to test the potency of expired cake mix. The same is true for an expired brownie mix. You need to bake it to see for yourself. When dealing with an expired pancake mix, you can always cook a single pancake as a test, and if it’s flat and dense, add the baking powder or soda needed, and continue cooking.

Now, the only question is how much baking powder to add to your mix. Let’s cover that.

Cake mix best-by date
Cake mix best-by date

How to Revive Expired Cake Mix

To revive your expired cake mix, add one teaspoon of baking powder per cup of cake mix. If the mix is less than half a year past the printed date, reduce that to one teaspoon per two cups.

Those are some rough estimates of how much baking powder you need to make your expired cake mix potent again.

Next, let me tell you how I came up with this recommendation so that you know I’m not just making it up as I type.

To come up with this, I analyzed a couple of homemade cake mix recipes. To keep this brief, let’s limit the discussion to this one from and this one from, both with great user reviews.

In the former, the author recommends 3½ teaspoons of baking powder per a bit less than 4 cups of the mix. In the latter, we add 12 teaspoons of baking powder per 12½ cups of the mix.

As you can tell, in both of these, their authors recommend a bit less than a teaspoon of baking powder per cup of the final mix. That’s why I think a teaspoon per cup is a good ratio to aim for, and it’s okay to add a bit less.

Now, if the mix has just passed its expiration date, it’s probably best to use it as is. But if it’s more than a month or two beyond that date, a quarter up to a half teaspoon per cup should help.

Finally, if the mix is more than six months past its date, assume the leavening agent is done for and add the whole amount.

Use up your expired cake mix is some low-stakes weekend baking, not when you want to impress your spouse or extended family with your baking skills. I cannot guarantee that adding the mentioned amount of baking powder will yield perfect results. Sometimes, it might be too much leavening, which is also far from optimal.

Prepping cake batter from cake mix
Prepping cake batter from cake mix

How Long Does Cake Mix Last?

Cake mix has a shelf life of about 12 months and retains potency for a couple of months past its date.

Unfortunately, there’s no good way to tell how long after the printed date it will stay potent. Because of that, if it’s more than a month or two past the best-by date, I suggest adding extra baking powder to ensure your cake rises properly.

I outline the details on that in the section on reviving expired cake mix.

How to Store Cake Mix

Store your cake mix in a cool and dry place, away from sunlight, and sealed tightly. If you don’t use the entire bag in one go, transfer the leftovers to an airtight container or a freezer bag, or at least seal it using a sealing clip.

That’s about all it needs.

The most important thing is to have it well sealed.

That helps keep your cake mix away from moisture, ensuring it cannot absorb any and potentially grow mold. And it also keeps pantry bugs at bay.

If you wish, you can refrigerate or freeze cake mix, but it doesn’t benefit much from it. It’s not powdered milk, which retains quality longer when refrigerated due to its fat content.

Having that covered, let’s briefly talk about when you should actually toss your cake mix.

Lemon cake topped with lemon curd

How to Tell if Cake Mix Is Bad?

Discard your cake mix if:

  • It’s infested. If you find any pantry bugs in your cake mix, it’s done for. Toss the package and go through nearby products to make sure they aren’t infested too. Pantry pests spread like wildfire.
  • It’s moldy or has wet clumps. Wet clumps or mold are sure signs that moisture got to the powder. And if things get this far, it’s best to play it safe and toss the entire thing. Small dry clumps are fine, and you can break them up using a fork or a sieve.
  • It smells off. This one isn’t that common, but if your cake mix stinks, it’s fairly obvious it’s no good.
  • It’s too old. If your cake mix is past the best-by date and you don’t feel comfortable using it, that’s a good enough reason to toss it. I can’t give an exact period because it’s different from person to person, but if I found one more than two years past its date, I’d discard it.

If anything else about your cake mix doesn’t feel right, trust your gut and toss it. Better safe than sorry.

Cake Mix Shelf Life and Expiration Summary

Thanks for reading this short guide on cake mix. Here are the main takeaways:

  • Cake mix doesn’t go bad in the traditional meaning of the word, but it doesn’t stay potent forever. And if stored long enough, it’ll lose potency and make flat and dense baked goods.
  • If your cake mix is more than two months past its best-by date, add half a teaspoon of baking powder per cup to revive it. If it’s more than six months beyond its date, double that to one teaspoon per cup.
  • Store cake mix in a cool and dry place, sealed tightly. Refrigeration and freezing, while possible, don’t help that much.