Does Brownie Mix Go Bad? How Long Does It Really Last?

Found a brownie mix sitting in a cupboard for who knows how long? It’s probably out-of-date, and you’re wondering: does brownie mix go bad?

Or maybe you have friends over for coffee in a day or two. And you want to know if that brownie mix that’s 3 or 4 months after its date is still safe and okay to use.

If that’s what has brought you here, you’re in the right place. In this article, we’re going to cover all things related to brownie mixes:

  • expiration – does it expire and whether you can tell it’s gone bad
  • shelf life – how long you can expect it to make decent brownies (here’s how long brownies last) and how you might try to “fix” your expired brownie mix
  • storage – how to go about it

Interested? Let’s dig in.

Brownie mix box in hand
Brownie mix box

Does Brownie Mix Go Bad?

Brownie mix doesn’t go bad in a way that it’s unsafe to use, but it doesn’t last forever either.

Over time, the quality of some ingredients degrades, which results in less than ideal texture and taste.

What’s more important, brownie mix contains a raising agent that doesn’t retain potency for all that long. And if that raising agent doesn’t do its job, you end up with a flat super-wet-inside brownie that you will likely throw out.

Ingredients of a typical brownie mix include:

  • flour
  • cocoa powder or chocolate
  • leavening agent, like baking soda (sometimes labeled as sodium bicarbonate) or baking powder
  • salt
  • sugar
Brownie mix insides
Brownie mix insides

As you probably know, flour, cocoa powder, and even chocolate can last for quite some time. Sugar and salt retain quality even better.

The only issue is with baking powder or baking soda, neither of which retains potency for an extended period. And since the dry ingredients are all mixed up, you cannot test the potency of the raising agent alone.

So, can you use an expired brownie mix? Yes, but if it’s more than 3 or 4 months past its date, do it in a low-stakes situation. Choose a leisurely weekend and go for it. If it turns out well, great. If not, no big deal.


If it’s not a low-stakes situation, you can still bake that brownie. Just do it a day earlier so that if you’re not happy about its quality, you still have time to buy something else.

Brownie before baking
Brownie before baking

How Long Does Brownie Mix Last?

Brownie mix should work well for 3 to maybe 6 months after the date on the label.

After that period, the raising agent will likely start to lose potency, and the brownie might turn out flat-ish and wet (instead of moist) inside.

Of course, this 3 to 6 months period is only an estimate. And you cannot really tell how long does brownie mix last after the “expiration” date.


The date on the label isn’t an expiration date and has little to do with food safety. It’s usually a “best-by” or “best before” date that indicates how long, at the very least, the mix should retain quality.

Brownie mix date on the label
Brownie mix date on the label

One thing you might want to try out if your brownie mix is more than half a year past its date is adding a bit of leavening agent to make up for the lost potency.

Here’s how:

  1. Check if your mix uses baking powder or baking soda (sodium bicarbonate).
  2. Find a brownie recipe that’s similar to your mix. That means it yields a similar (size- and texture-wise) brownie and uses the same raising agent.
  3. Check how much of the raising agent the recipe calls for.
  4. Add the baking soda or powder to your dry mix. If your mix is 6+ months after its date, use one-fourth of what the recipe uses. If it’s more than 12-18 months, use half. Two years or more? Use three-fourths or even the whole amount (if it’s “expired” for like three years).

I cannot guarantee the results of this “fix” because every mix is different. But the logic behind it is pretty simple: the leavening agent gradually stops working, and we try to mitigate that by adding some to make up for it.


If you’re using a long-forgotten brownie mix, assume the resulting brownie won’t be all that great. If it turns out well, you’ll be positively surprised.

Baked and served brownie
Baked and served brownie

How To Store Brownie Mix

Store your unopened brownie mix in a cool and dry place. A cupboard in the pantry or kitchen works just fine.

If your brownie mix is way more than you need (i.e., it yields a big brownie, and you only want a couple of pieces), you can usually use half of the mix and store the rest for later.

If your mix included a couple of separate bags (e.g., one with dry ingredients, one with chocolate, and another for the topping, like mine did), pack the leftovers the same way. So if there were three bags, you should end up with three freezer bags or containers with the remaining ingredients.

Properly stored leftovers will last an extra couple of months, so there’s no need to rush using them.


If you have a couple of bags with ingredients, consider putting them all in a larger airtight container or bag. This way, everything stays together, and that’s probably the best way to go about storing leftover brownie mix. Adding a name on the label could help as well.