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How Long Does Cornstarch Last? Does it Go Bad?

Do you often find yourself left with bags of cornstarch after baking a cake or making gravy and wondering to yourself: does this expire? How long is it good for?

If any of these questions have been crossing your mind, then worry not! We’ve got the answers.

Cornstarch has an incredibly long shelf life, usually lasting one to two years in its unopened package— sometimes even longer if stored properly!

Here, we’ll explore all the factors that can impact how long your cornstarch will last and answer some common questions about storing it safely.

So grab your bag from w/e cupboard back home where it’s gathering dust, make sure everything else in there is secure too-like extra flour and sugar–and let’s dive into the world of starches!

What is Cornstarch?

Cornstarch is a fine, powdery starch that is derived from corn.

It is used as a thickening agent in many recipes, such as sauces, pie fillings, puddings, and gravies.

When cornstarch is mixed with water, it forms a gel-like substance that can be used to thicken or stiffen food.

Cornstarch can also be used as a coating for fried foods, such as chicken or fish.

How to Store Cornstarch?

Any good cook knows that cornstarch is a versatile ingredient that can be used for thickening sauces, gravies, and puddings.

However, if you don’t know how to store cornstarch properly, it can quickly become lumpy and unusable.

The key to storing cornstarch is to keep it dry.

Moisture causes the cornstarch granules to swell and clump together, so it’s important to avoid exposure to humidity.

One way to do this is to transfer the cornstarch to an airtight container.

Mason jars or zip-top bags work well for this purpose.

You can also add a desiccant pack to the container to absorb any excess moisture.

Once the cornstarch is stored in an airtight container, it should be kept in a cool, dark place.

The pantry or cupboard are both good options.

With proper storage, your cornstarch should stay fresh for up to 6 months.

How Long Does Cornstarch Last?

Cornstarch is a powder made from the starch of corn kernels.

It’s commonly used as a thickening agent in sauces, gravies, and pies.

You can also use it to make homemade laundry detergent, shampoo, and face powder.

So, how long does cornstarch last? When stored properly, cornstarch can last for up to 2 years.

But if it’s not stored properly, it can go bad in as little as 6 months.

The best way to store cornstarch is in a cool, dry place.

That means your pantry or cupboard is a good option.

You can also store it in the fridge or freezer if you want it to last even longer.

Just be sure to put it in an airtight container so it doesn’t absorb any moisture from the fridge or freezer.

If your cornstarch has gone bad, you’ll notice that it has clumps in it or that it has changed color.

If you see either of these things, throw it out and get a new container.

How to Tell If Cornstarch is Bad?

There are a few ways to tell if cornstarch has gone bad.

The easiest way is to simply check the expiration date on the package.

If it has passed, then the cornstarch is most likely no longer good.

Another way to tell is by looking at the cornstarch itself.

If it has changed colors or is lumpy, then it has probably gone bad and you should throw it out.

Finally, smell the cornstarch.

If it has a sour or musty smell, then it has gone bad and you should not use it.

If you’re not sure whether the cornstarch is still good, the best thing to do is to throw it out.

It’s better to be safe than sorry when it comes to food safety.

Can You Freeze Cornstarch?

Many people don’t realize that cornstarch can actually be frozen.

While it may seem strange to freeze something that is typically used as a thickening agent, there are actually many benefits to doing so.

For one, it can help extend the shelf life of cornstarch.

Additionally, freezing cornstarch can also make it easier to use later on.

When it comes to freezing cornstarch, the best way to do it is by using an airtight container.

This will help to prevent freezer burn and keep the cornstarch fresh for longer.

It’s also important to note that you should only freeze what you plan on using within the next few months.

Any longer than that and the quality of the cornstarch will start to decline.

If you’re looking for a quick and easy way to thicken up a sauce or soup, then frozen cornstarch is a great option.

Simply take out a tablespoon or two from the freezer and add it into your dish.

The cornstarch will quickly dissolve and thickening up your dish in no time.

What are Some Uses for Expired Cornstarch?

There are actually quite a few uses for expired cornstarch.

Here are just a few:

  • Make your own DIY dry shampoo: Just mix some cornstarch with cocoa powder (for dark hair) or baby powder (for lighter hair), and voila. You’ve got a cheap, all-natural way to keep your hair looking fresh in between washes.
  • Use it as a natural deodorant: Simply apply some cornstarch to your underarms and you’ll be good to go. The cornstarch will absorb any moisture and help keep you feeling fresh all day long.
  • Absorb grease stains: Got a grease stain on your shirt? No problem. Just sprinkle some cornstarch on the stain, let it sit for a few minutes, then brush it off. The cornstarch will help absorb the grease so that you can easily wash it away.


We hope this blog post has been helpful in answering some of your questions about cornstarch and its shelf life.

Although it is possible for cornstarch to go bad, it usually takes a very long time for this to happen.

If you have any further questions, please feel free to contact us.

How Long Does Cornstarch Last? Does it Go Bad?

5 from 1 vote
Prep Time 10 minutes
Cook Time 10 minutes
Total Time 20 minutes
Course Shelf Life
Servings 1 Serving


  • Cornstarch
  • Air-tight containers or Ziplock bags
  • Labels and markers


  • Store your product in an labelled container in a cool, dark place like the pantry or fridge.
  • If your food is frozen, allow it to thaw in the fridge before cooking.
  • Make sure to look for signs that your food has gone bad before eating it.
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