Does Cornstarch Go Bad? | Build a Stash

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Key Takeaways

  • Cornstarch is a thickening agent that can provide nutrition in an emergency situation.
  • It can last for up to 3 years if properly stored and not exposed to moisture or bacteria.
  • Before consuming cornstarch at any time, you should first check for clumps and mold.

You may have read about cornstarch having an indefinite shelf life. While cornstarch may not go bad for a long time, there are times it may not be safe to eat.

Cornstarch can go bad if it comes in contact with moisture and bacteria. Though cornstarch can have a relatively long shelf life of up to three, it must be securely stored in an airtight container in a cool and dry place to not go bad.

Though cornstarch manufacturers typically suggest cornstarch not be used after 2 to 3 years, it might be safe to eat cornstarch beyond that time. If you are in a survival situation and are low in food resources, consuming cornstarch might be a feasible option for nutrition.

Table of contents


What Is Cornstarch?

Cornstarch (also spelled corn starch) is often used as a thickening agent for sauces, fillings, soups and is not meant to be eaten raw in powder form.

Eating raw cornstarch powder may cause an unpleasant reaction in your mouth, throat, and stomach.

However, if you are desperate for food and cornstarch powder is one of your only food options, dealing with potentially irritating digestive effects might be worth it.

A more ideal situation for ingesting cornstarch would be to mix it with a heated liquid such as water or broth.

Corn Starch For Survival

You may not get a ton of nutrients from cornstarch, but the small amounts of carbohydrates, protein, and fiber it contains may be better than nothing.

Cornstarch and other foods with a very long shelf life are often tightly sealed with advanced food safety techniques to minimize the amount of air and contaminants inside a package.

A package of cornstarch that has never been opened will likely contain cornstarch that is much more fresh than an equally old opened and sealed cornstarch container.

When a package is opened, outside air makes its way inside the package and makes contact with the food item.

Though packaging might seem tight and secure, it’s not uncommon for moisture and bacteria to seep in over time.

Even if the package is in a clean, cool, and dry area, the air around a package may contain trace levels of contaminants that could gradually make their way inside the package.

Many plastic and glass containers have secure locks to ensure a fine powder like wheat flour or cornstarch is stored properly.

When Does Cornstarch Go Bad?

Though corn starch might be safe to eat after the “best by” date on its packaging, you should use this date as a gauge for its freshness.

If you are not in desperate need of food, it might be best to avoid consuming cornstarch that is older than the date printed on its package.

If you have little to no other food resources, it might be fine to eat the cornstarch if it is mixed into a liquid that is sufficiently heated up.

Regardless of the date on the packaging, you should carefully inspect the cornstarch before using it.

You should make sure the corn starch is dry, loose, smooth, and has an even color that isn’t too dark.

Cornstarch powder that has discoloration or mold may have been exposed to significant moisture and bacteria.

Cornstarch with noticeable texture or color changes should be avoided and thrown out to prevent it being accidentally consumed.

It might be safer to eat lumpy cornstarch that doesn’t have discoloration or indications of mold, but there may still be a risk of eating bad cornstarch if it isn’t in a completely dry and powdery state.

What Does The Best By Date Mean For Cornstarch And Baking Powder?

Cornstarch brands like Argo, Clabber Girl, and Rumford often print “best by” dates on their packaging as a general marker of how long the cornstarch will last.

Since cornstarch is an incredibly resilient food product that can technically last much longer than a few years, it’s difficult to know exactly when it will go bad.

If cornstarch were stored in a lab that can completely protect it from moisture and bacteria, the corn starch could probably last much longer than a printed “best by” date.

Since storage options are typically not as secure as a lab situation, even if you freeze cornstarch, manufacturers don’t have all the information they need to produce a precise expiration date.

Consumers are likely to store cornstarch in a wide range of conditions, so manufacturers may consider the average conditions when establishing a “best by” or expiration date.

Though it’s probably best to consume cornstarch as early as possible, it might be safe to consume it after any printed dates.

For legal reasons, manufacturers may want to limit the printed cornstarch shelf life of their products to reduce the likelihood of someone getting sick and suing them for it.

A manufacturer may print a date that is far earlier than the actual expiration date, which means cornstarch may not go bad until a time much later than the printed date.

To be on the safe side, you should always inspect the corn starch before consuming it or mixing it with other food.

A package that is only a few days old might be unsafe to use if bugs and bacteria have found their way to it.

Why Should I Store Cornstarch In An Airtight Container?

To maximize the shelf life of cornstarch, you should keep it in an airtight container in a dry and cool place.

Good containers might include jars or boxes made of a durable plastic, metal, or glass with a latchable lid that prevents air from getting in.

Many of the latest factory-produced containers are made with materials and technology that are very effective for keeping food safe.

Container brands like Rubbermaid, OXO, and Snapware often have affordable and high-quality kitchen storage solutions that can be used to effectively store cornstarch.

Though keeping a package unopened might be best for optimizing the shelf life of the contents, you should close and securely seal the container as soon as possible if you must open it.

This is also true of corn flour, wheat flour, baking soda, and any other pantry staple you might use as a thickening agent.

If you don’t plan to use the cornstarch any time soon, it might be helpful to reinforce the container with other wraps and other materials to give it added protection against spoilage.

How Should I Eat Corn Starch?

Cornstarch is a generally flavorless powdered substance that is not pleasant to eat in a raw form.

The powder can clump up in the mouth and throat and be difficult to swallow.

Once it gets into your stomach, it might cause digestive issues as it may not be smoothly processed in your intestines and other parts of your digestive system.

To make corn starch easier to eat, you should mix it with liquids like water or broth.

You can actually make delicious sauces, soups, gravies, pie fillings, and other food items with cornstarch.

If you don’t have any other foods to use with the cornstarch, eating the cornstarch doesn’t have to be an unpleasant experience.

Mixing it with water or another easy-to-access liquid along with basic seasonings or sweeteners might make it more palatable to consume.