» Does Cornstarch Go Bad?How Long Does It Last?

Does Cornstarch Go Bad?How Long Does It Last?

Does Cornstarch Go Bad How Long Does It Last
Image: Lucky Belly

There are certain food items that you rarely use, but you have them on your shelf at all times. One of such items is cornstarch! This modified starch made from corn kernels is often used to thicken and enhance soups and creams.

Though cornstarch might not be the first thing you remember while making your grocery list, you surely make sure that you have it available for days when you want to make some thick and slurry delicacies, which is not always.

So until when can you use your opened or unopened cornstarch? Let’s dive deep and find out!

Does cornstarch go bad?

Does cornstarch go bad
Image: Lucky Belly

Almost all the food items go bad, and even if it doesn’t, it will surely degrade in quality and taste. The same is the case for cornstarch!

If you store your packet of cornstarch in a proper manner, its shelf life is indefinite. But if not, your cornstarch will lose its potency, or worse, will go moldy over time. If you don’t want to use old cornstarch and here’s a list cornstarch substitutes.

So, how to store your cornstarch in the best possible way? We’ll discuss it later in this post.

How long does cornstarch last?

How long does cornstarch last
Image: Lucky Belly

Now, let’s get to the point. You want to know if or not you can use your months’ old cornstarch, don’t you? Well, feel free to use it! In simple words – the shelf life of cornstarch is indefinite! But does that mean you leave your cornstarch jar improperly stored? Absolutely not!

Cornstarch, like any other powdered food item, has less or almost no moisture content. So, there’s no free water content for bacterial and fungal growth. However, if not stored under appropriate conditions, molds might find your cornstarch appealing.

And, if you leave your cornstarch jar or container open and unsealed, don’t be surprised if you see ants feasting on it. Moreover, ants are prone to death after eating too much cornstarch. So, what can be worse than seeing ants on your cornstarch jar? Dead ants!

Thus, cornstarch is not prone to spoilage. And, it doesn’t much degrade in quality either. Even if you feel that it has, just add some warm water and see for yourself! However, cornstarch must be stored in an appropriate condition for storage. Later in this post, we’ll tell you how!

At pantry

Cornstarch (Opened or unopened)


3 Tips to tell if cornstarch has gone bad

3 Tips to tell if cornstarch has gone bad
Image: Lucky Belly

Cornstarch is good to use indefinitely in your kitchen as it doesn’t lose its effectiveness with time. As stated above, you can safely use the cornstarch even after its best before date.

Sometimes you might be worried that the quality of your cornstarch has degraded once it’s past its best by date. But when you mix the same cornstarch with hot water, the effectiveness of the cornstarch will be more or less the same.

Here are a few tips by which you can say that your cornstarch has gone bad, and it’s time for you to get rid of those packets from your kitchen.

1. Moldy cornstarch

If your packet of cornstarch is exposed to moisture somehow, then you might want to look for the signs of molds or any organic life growing inside your cornstarch container.

If your container has been exposed to moisture, then it might go moldy within a few days. If you find such moldy cornstarch in your kitchen, the first thing you need to do is to get rid of that container right away.

2. Clumping

Sometimes, when your cornstarch is exposed to moisture, though the powder seems fine, it might have some small clumps.

If you notice such clumps, you must consider shifting the powder cornstarch to another airtight container before using it again. And remember not to introduce moisture to your cornstarch container ever again!

3. Presence of bugs

Similar to molds, your container of cornstarch may contain some pantry bugs inside it. If such a case occurs, then you must immediately get rid of that container from your pantry.

At last, you need to understand that taking good care of your cornstarch container ensures that it lasts longer in your kitchen cabinet and is essential to extend its shelf life.

3 Tips to store cornstarch

3 Tips to store cornstarch
Image: Lucky Belly

As you know by now, cornstarch has a very long shelf life only if you are able to store it safely. However, like any other powdered food item, cornstarch is also low-maintenance when it comes to its storage. Here are a few tips you can follow to store your cornstarch and use it for a long time.

1. Store in an airtight container

You must be careful and tightly close your packet of cornstarch once you open it and are not in use. You can find cornstarch in a plastic container in the market, and this container works perfectly for storing the cornstarch powder after you open and use it once.

But what if you buy cornstarch that doesn’t come in a resealable bag? If that’s the case, you should immediately need to transfer your unused cornstarch powder into an airtight container or a resealable bag.

An airtight container helps you prevent your powder from the outside moisture and false odor, which can alter the effectiveness of your cornstarch.

Not only this, your packet of cornstarch attracts the insects and bugs of the pantry, and a resealable and airtight container helps you to keep away these tiny villains from your food.

2. Keep your jar or bag of cornstarch in a cool dark place

You can simply store cornstarch the same way you store wheat flour or powdered sugar. That means you can store your cornstarch in places that are dry and relatively cool.

As most of the food items, cornstarch is also best stored in the cold and dark place in your pantry. The pantry is the best option, but a kitchen cupboard is fine as well when it comes to the storage of cornstarch.

3. Keep moisture as bay

Water and cornstarch have an interesting relationship. Though they’re made for each other, they shouldn’t come together unless you’re cooking or making a recipe.

When moisture is introduced to cornstarch, you might notice some clumping, and the damp cornstarch is prone to inviting molds over to grow on them.

Risks of consuming expired cornstarch

Risks of consuming expired cornstarch
Image: Lucky Belly

Firstly, you should be clear that the expiry date mentioned on the packaging doesn’t necessarily mean that the food item is inedible once the date crosses. It simply means that the quality and flavor of the item might have degraded by that time.

However, when it comes to cornstarch, it doesn’t even lose its quality and does the job even past the expiry date. Even years old cornstarch can thicken your soups and creams as effectively.

So, as we’ve said earlier, cornstarch can maintain its quality indefinitely. Thus, even if the expiry date on your cornstarch packet has passed by, feel free to use it to enhance your soups and dishes. You’ll most likely experience no issue at all.

However, make sure that you’re not using moldy cornstarch as you might experience allergic reactions as well as respiratory problems to certain mycotoxins.

Can you freeze cornstarch?

Have you been wondering whether or not you can store the packet of cornstarch inside your refrigerator or freezer? Though freezing is considered a good option for many food items well, it shouldn’t be the first choice if you’re trying to store your cornstarch for the long term.

First of all, the shelf life of cornstarch is incredibly long. You can relax and use your months or even years old cornstarch if you want to. So, you don’t need to freeze it at all.

Secondly, one of the main purposes of a freezer, when it comes to food preservation, is to freeze the moisture content within the food items and to make it unavailable to microorganisms.

But since cornstarch is in powder form, we don’t see why freezing would benefit its long-term storage. Finally, freezing your cornstarch might impose an unnecessary risk of moisture exposure, which you can avoid by simply storing it in your pantry cupboard.

However, if freezing is your choice, you can keep your cornstarch powder inside the freezer if you want to, but as we’ve said before, this doesn’t help it much.

And, if you have stored your powder inside the freezer, you must keep in mind that your container is air sealed. Else your cornstarch powder will withdraw the moisture from inside the freezer, which ultimately leads to the spoilage of your cornstarch powder.


We’ve discussed all that you need to know about cornstarch in this post. Does cornstarch go bad? How to tell if it has? What are the tips when it comes to storing your cornstarch? Well, by now, you know it all!

We all know that the fresher the food item, the better! But when it comes to cornstarch, stock up on it as much as you want. And, feel free to use your stored cornstarch to make that delicious soup. Or, were you planning on making homemade ice cream?

Leave a Comment