Does Cornstarch Go Bad?

Does cornstarch go bad or not? Here's the answer that you are looking for, including information about storage and more.

Every once in a while, you may come upon a recipe that calls for cornstarch.

In a panic, you check your cupboards, remembering that you bought some cornstarch some time ago. You’re only left to ask, “is it still any good?”

Fortunately, even though cornstarch is an item you only buy every once in a while, it can last a good amount of time. Even if it may be considerably past the expiration date on the container, your question remains: “Does cornstarch go bad?”

Cornstarch is primarily used as a thickening agent for sauces and gravy, and it is basically a powdered form of starch extracted from corn kernels. Depending on what you prepare, it may not be used often, and unfortunately, it is not available for single-use purposes.

This leads to 3 important points that must be discussed:

  • How should cornstarch be stored?
  • How long can cornstarch last?
  • How long is cornstarch usable?

Related:Does Flour Go Bad?Does Baking Powder Go Bad?Does Baking Soda Go Bad?

How Should Cornstarch Be Stored?


If you use wheat flour often, then you already have a good idea of how to keep cornstarch usable. You don’t need to worry about temperature, so it does not need to be put in the refrigerator to prolong its use – room temperature is ideal.

If you live in a humid climate, it’s best to keep cornstarch in a dryer and cooler area, and it is also a good idea to store it in a resealable baggie. The container it comes in should be sufficient, but the baggie will help ensure that no moisture should enter.

Like baking soda, cornstarch can absorb unwanted odors, which will alter taste. Common household bugs can also get into cornstarch, so transferring it to a resealable, airtight container may be best.

How Long Can Cornstarch Last?

cornstarch on table

Technically, cornstarch can last a long time, especially if kept as described. The biggest enemies of cornstarch are moisture and common kitchen pests.

If you see any indication of mold or discoloration, it is probably best to throw it out. This is evidence that it has had prolonged exposure to moisture. As mold cannot form without the help of water, it’s best to err on the side of caution.

If bugs have had their way with it, you can find out by sifting through the cornstarch itself. Just simply shaking the container or using a spoon to stir it around would reveal any critters who have invaded. If you see any specks in there, throw it out.

If you see humidity and some clumps in the container, it’s okay. This means it got a little wet. But, if you don’t see mold, it’s all good. Just use a spoon to make it a fine powder again.

How Long Is Cornstarch Usable?


As long as the easy guidelines here are followed, there should be no issue – cornstarch should last forever.

Just remember these three tips discussed:

  • Keep cornstarch in an airtight, sealed container
  • Protect the cornstarch from moisture the best you can at room temperature, especially in tropical climates
  • Keep outside pests and bugs away

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Michelle Olsen

Michelle loves writing about food and helping others make better food. She cooks and prepares food daily for her little girl and spends some of her free time researching the best food storage practices.