How Long Does Cake Mix Last And The Best Way To Store It

So, it is more common than you would imagine that you get some cake mix and leave it in your pantry, only for more and more food to get stacked in front of it. Then all of a sudden it has been years and it is only now being rediscovered.

Of course it is past its best before date, but does that mean that it will not work? This guide will give you all the information you need on cake mix that is past its prime, and when and when not to use it.

How Long Does Cake Mix Last And The Best Way To Store It

So, if you have found some ancient cake mix and are craving something sweet, keep reading!

Making a cake from scratch is all well and good, however, sometimes and in some situations, nothing can beat the convenience and consistency of a cake mix cake.

You still get the same satisfaction and fun of baking something yourself, the amazing results, but without all the complexity, extra cost of ingredients and potential for failure.

We all know that if you follow those instructions, you will get a cake that looks almost identical to the box.

However, with how common cake mix boxes go on sale, and how easy it is to buy some and forget about having them, it is very easy to forget that you have it.

And since their expiration dates are usually so long, you always think that you have longer than you actually do until that time is up. However, there is a catch when it comes to considering how long a cake mix will last.

Turns out, most cake mixes do not expire like other food items do. The use by date you will see on the box is usually a recommendation of when you will get the best results when you make the cake.

So, if you try making the cake after the date, there is a chance that it will not bake as well, or might taste less good, however, it is still edible since none of the fresh ingredients are included.

However, there are ways that your cake mix can expire under certain circumstances we will go over.

So, this guide will go over all the different pieces of information you need when it comes to dealing with your cake mix, no matter how far past its expiration date is.

There is a chance that you will want to throw your cake mix away, however, there are ways you can save it. We will also give you some great advice for the future on how you can store your cake mix to make it last even longer.

So, if you love working with cake mixes, keep reading!

Does Your Favorite Cake Mix Expire?

As we referenced in the previous section, you will likely be surprised to hear that cake mixes do not have an expiration date.

You are probably looking at the date on the bottom of your cake mix and thinking that we are wrong, but in most cases this will be a recommendation of when to use it by to get the optimal results.

The cake mix will still be edible past this point, however, it will likely not bake as well, and the flavor will likely not be amazing.

Most of the most popular cake mix manufacturers like Duncan Hines, Pillsbury, and Betty Crocker have a suggestion on their cake mixes, none of these use an actual strict expiration date.

While you can find other cake mix manufacturers, you will find that most cake mixes are produced in a similar way, and they will all have a suggestion like these, instead of an actual expiration date like you might assume.

Officially according to the USDA, a best by date has no indication of the safety of the product. It is simply a recommendation and an assurance that the quality of the product is guaranteed before this date.

So, once you have let your product go past this date, there is no guarantee that the quality will be what is advertised. This is why dry mixes like this and cereals are generally safe indefinitely.

These can be stored at room temperature and you will not have to worry about them going out of date. So when dealing with an old cake mix, do not worry about safety!

It might be interesting to learn that expiration dates were not introduced until the 70s and cake mix has been around since the 40s. So, what was done before expiration dates were introduced?

People simply used observation skills to tell if something was appropriate to use. You can usually use a simple combination of sight, smell, and taste to tell if something is out of date.

So, even if something is past its expiration, does not mean it is always unsafe to eat.

Different Cake Mix Manufacturers And Expiration Dates

As we mentioned in the previous section, all of the most common cake mix manufacturers have best before dates on their products and no strict recommendations.

All of these companies recommend that you use their products before the expiration date, however, they all mention that when you are using a product past the recommended date, that the taste and the bake quality is not guaranteed and you are much more likely to end up with a cake that is not to the quality assured on the box.

Shelf Life Of Cake Mix

If you do not know exactly what the shelf life of a cake mix means, this is how long the product will be considered acceptable to be sold and consumed after it has been produced.

You will generally find that the shelf life of most cake mixes will be somewhere between 6 months and a year. So, once the best before date has been passed, the quality of the mix will not be perfect, and stores will usually reduce the cost.

However, there are still some great recipe ideas that we use expired cake mix for to get great results!

Factors That Impact Cake Mix Shelf Life

While we have mentioned that the shelf life of a cake mix does not actually mean that it cannot be used after a certain point, that does not mean that the cake mix does not feature certain qualities that make it expire quicker.

There are actually 2 main factors worth considering that will impact the shelf life of your cake. These are the raising agent that is used, as well as how it is stored.

In this section we will go over these two main factors as well as a couple other factors that impact its quality as well!

Raising Agents

As we mentioned in the previous section, one of the main factors that impacts the quality of cake mix is what leavening agents and raising agents are used in it. For example, if baking soda or baking powder is used.

These are ingredients that when they are being baked, will release gasses which will make your batter expand and eventually make the cake rise. These also impact the final texture of the cake.

The issue is that these agents will eventually lose quality over time, so the longer you leave the cake mix, the worse the rise of the cake will be. This can also ruin the texture of your cake as well.


One of the main considerations you want to make when you are working with cake mix is how you store it. This is because how you store your cake mix will directly impact its shelf life.

This is even more worth considering if you are using cake mix that has already been opened with the pack not being completely full,

If your cake mix has not been opened and is in the box it originally was packaged in, you want to keep this in a dark and cool environment to make it last as long as possible.

You will also want to check the box before you use it to look for signs of infestation, mold, or moisture.

Now, if you have cake mix that you have already opened, then you want to keep the cake mix in an airtight container. You can even find that some cake mix manufacturers include a zip lock bag with their cake mix which will make it perfect for resealing.

Then if you want extra protection for your cake mix, then we recommend keeping this bag in a container with a tight lid as well. There are some signs you want to look out for when inspecting open cake mixes that you are storing.

Exposure To Oxygen

One of the main things that will detract from the quality of your cake mix when it is opened is the oxygen exposure that the mix has faced. Of course, if your cake mix has never been opened it will have had very little oxygen exposure, so it will last as long.

This will prevent it from becoming rancid through oxidation. Once the package is open it is much more likely to face oxidation, this will give it a dominant old flour taste over time which is unpleasant.


When your cake mix has been opened it will have been exposed to direct sunlight and this will put it at a higher temperature than it is usually at. This heat can also increase the humidity inside the bag and this is something that you want to avoid.

This is because if the humidity creates moisture, this will create an environment in the cake mix that can make bacteria thrive. So, make sure to keep your cake mix in a cool environment, whether it is opened or not. 


If your cake mix pack gets any signs of moisture, this might be a sign that you should throw away your cake mix. The reason for this is, like in the previous section, moisture is very likely to be a sign that bacteria can thrive in the cake mix and this can also cause mold.

This should be something you keep an eye out for if you live in a humid environment especially. If mold forms in your cake mix this can create mycotoxins, and these can cause stomach cramps and other foodborne illnesses, so throw it away if you see this.

What Cake Mix Flavor Will Last The Longest

If you are worried that only certain types of cake mix will last, then luckily, you do not need to worry. This is because most types of cake mix are made with the same ingredients, and flavor add ins will usually not cause any major issues.

So, do not worry about needing to stick to one specific brand if you want it to last for a longer time. Because of this, you can just focus on getting the flavor of cake mix which you like the most.

However, there is one factor that can impact the shelf life of your cake mix that is slightly related to the flavor. This is if your cake mix comes with any mix ins or other ingredients that are not just a cake mix.

This could be a packet of sprinkles, or candies, or even frosting. If any of these, or something similar are in the cake mix then these will need to be closely inspected before you add them to the cake.

The cake mix itself should be fine, but these add ins might need to be discarded and replaced, so keep this in mind!

Best Way To Store Cake Mix

So, if you have been reading the guide up to this point, you can probably surmise some key aspects of storing cake mix that will impact its quality.

The main thing you want to focus on when it comes to storing cake mix is that you limit the exposure the cake mix has to any oxygen, as well as light, heat, and any humidity or moisture.

If your cake mix is unopened, keep it in the original package for as long as possible and then keep it somewhere dry and cool. And if it is opened, put it in an airtight container somewhere dry and cool as well!

You can find some bakers suggesting that you can store your cake mix in your fridge or your freezer and that this might improve the shelf life. However, there is not that much proof for this.

Because of this, we actually recommend against this, since storing in the fridge or freezer introduces a whole other variety of variables like moisture and temperature that are worth avoiding. Also, for most people, storage in the fridge and freezer is usually limited.

Signs Your Cake Mix Has Spoiled

So, if you are using cake mix and you just want to make sure that it is safe to consume, there are some simple steps you can take just to ensure that it is safe to eat.

As we have mentioned a few times, you do not have to worry too much about the expiration date. However, as we have established, time is not the only factor that can impact the quality of your cake mix.

Because of this, this section contains some factors that you should keep an eye out for if you want your mix to last as long as possible!

Package Damaged

The main sign to look out for that could indicate that your cake mix has been spoiled in some way is if there is any sign of damage to the box. This box will be an indication of moisture or if any pests have been able to make their way in.

You could also notice mold on the box so look out for this. This step literally takes seconds, but it could save you eating something you really should not be doing. Because of this, even if your cake mix is before the expiration date, just have a quick glance at the box. 

Appearance Changed

As you can imagine, the texture of a standard cake mix should just be a normal powder. Usually the intended appearance of a cake mix is not advertised and they only want to show the final cake product, so this step takes a more discerning eye.

You want to look out for if there are big clumps as this can be a sign of moisture. Of course some pieces might have clumped, but if the texture seems less like a powder, then this is bad.

Also keep an eye out for white, blue, or green spots as this is likely mold. The easiest way to check this is to sift your cake mix to look out for any issues!

Smell Changed

This is another step that just takes seconds but is really worth doing is just giving your cake mix a quick sniff. You will very quickly notice if your cake mix is off if it smells bad.

Usually a cake mix will have a neutral scent, or maybe a little like the intended flavor e.g. chocolate or vanilla. But if it smells bad or rancid, then this is a sign that you will not want to eat the final product of this cake mix!

How To Revive Old Cake Mix

It is worth noting that depending on how far past your used by date your cake is at, there are different steps you can take to try and revive your cake mix.

For example, you do not really have to do much if your cake is only really 6 months after the expiration date. However, after this point it is better to add some baking powder.

Now if it is passed about 12 months then you definitely want to add baking powder, and when it gets past 18 months then it is better to look for an alternate recipe since it is likely that the cake mix will taste rancid.

As we mentioned earlier, the leavening agent in the cake mix is the most likely ingredient to let down the cake mix and this is what you are going to want to fix if the cake mix is far past the expiration date.

There is unfortunately not an exact science to this, and knowing how much baking powder to add can be difficult. Also, it is worth mentioning that there are no guaranteed results when working with these methods!

More Than 6 Months After Best By Date

When your cake mix has gone over 6 months past the expiration date, this is when your leavening agent will have started to lose some potency and you will want to top it up to fix it.

The best proportion to do this at is about 3 teaspoons of baking powder for every 4 cups of cake mix that you have, so about 3.75 ml of baking powder for every cup.

Most cake mix comes in a 4 cup size, so this is why we recommend using 3 teaspoons if you do not know how much you are working with (Need to know how many teaspoons are in a tablespoon? See our guide here).

However, if your cake mix is a little further past the expiration date, then you might want to add slightly more baking powder, however, you do not want to have the inverse effect and ruin your cake by adding too much.

Does Cake Mix Last Longer In Mylar Bags

One of the best methods for storing your cake mix is in a Mylar bag since these are incredibly durable and will not let any light, oxygen or moisture damage your food, however, this all depends on what ingredients are in your cake mix.

Even though ingredients like flour and sugar can last years in these bags, you will likely still need to add some extra baking powder.

Do Not Want To Add Baking Powder?

If you do not want to add baking powder you can still use your cake mix to make something like cookies, or trifle since these do not need the raising agent.


Hopefully this guide has given you all the information you need to get the best results when you are working with cake mix.

As you have seen there is plenty you want to consider when working with this, but if you want to avoid all this trouble, remember that the sooner you use your cake mix the better the results will be.

We recommend only buying so much cake mix so you do not end up with more than you need, and when you are storing it, make sure you keep it somewhere easily visible so you do not forget about it too easily!

Mark Williams
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