How To Tell If Corn On Cob Is Bad?

Corn is both a vegetable and a grain, so it’s a little controversial as natural foods go. Is it healthy to eat corn on the cob? This is a decision that must be determined on a case-by-case basis. Some people have trouble digesting corn, so they should not eat it. Others digest it fine but eat too much! They should practice some self restraint.

Generally speaking, corn is a good source of both protein and fiber. If you can eat it in moderation without experiencing gastric distress, it’s a good addition to your diet. But how to tell if corn on the cob is bad? What happens if you eat bad corn?

Always Eat Corn When It’s Fresh!

what happens if you eat bad corn

When harvesting or purchasing fresh corn on the cob, you should realize that it’s a veggie with a short freshness period. It’s best if you can prepare it within 24 hours of purchasing or harvesting.

If you must keep corn in the fridge for a few days before cooking it, be sure it’s wrapped well in plastic or aluminum foil, and keep your fridge on a cold setting (35 degrees Fahrenheit).

Exposure to air will dry corn out and make it tough. No matter how well it’s wrapped, fresh corn should always be used within three-to-five days of picking or purchase.

How Long Will Cooked Corn Stay Fresh?

If you have leftover cooked corn on the cob, you can store it (tightly wrapped) in the refrigerator for three-to-five days.

Reheat it in the microwave by placing it in a microwavable dish and covering it with a damp paper towel. Reheat in 20-second increments, turning the corn between each increment.

Alternately, you can just put a little water on the stove to boil and drop the ears of corn into the boiling water for about 3 minutes.

This will cook it just slightly more, but it will still be tasty. Boiling eliminates the risk of having kernels burst or turn hard while microwaving.

Other ways of storing corn include freezing and canning.

How Can You Tell If Corn Has Gone Bad?

How Can You Tell If Corn Has Gone Bad

When you take uncooked corn on the cob out of the fridge, you may notice that some of the kernels have turned brown.

This is not a cause for great concern, but it does indicate that your refrigerator temperature was just a bit too warm for corn.

As long as there is no bad odor and/or slime, you can just cut the brown kernels off and prepare the corn as usual. If you notice any of these signs that your corn on the cob has spoiled, you should toss it:

  • Moldy, slimy appearance and feel
  • Rancid, moldy smell

When choosing corn at the market, examine the husks and the silk. If the tip of the husk and/or the silk are dark brown, the corn is a bit old. Look for fresh, green husks and tender white/yellow silks.

As with any vegetable, if corn is dark, mushy or smelly, it isn’t good.

Key Tips

  1. Corn on the cob should always be stored in the refrigerator at about 35 degrees F.
  2. Corn on the cob will stay fresh in the fridge longer if you leave the husks on while storing.
  3. Husked corn on the cob must be wrapped tightly in plastic or foil for storage.
  4. Raw corn on the cob should be used within 3 days of refrigerating.
  5. Cooked corn on the cob should be used within 5 days of refrigerating and within one year of freezing. After 8 months have passed, it may have lost some quality, but it is still safe to eat.
  6. Corn that has dried out has been grown in hot, dry conditions. While it is not dangerous to eat, it is not palatable.

What Happens If You Eat Bad Corn?

As with any food, if you eat bad corn you are very likely to experience symptoms of food poisoning, such as gastric distress, vomiting and diarrhea. It is also worth noting that many people are allergic to corn. If you are one of them, you might experience these symptoms when you eat fresh corn.

All-in-all, common sense dictates that we strive to eat food that is fresh, clean and correctly prepared. Always be sure to store corn correctly, use it promptly and cook it thoroughly.

If you want to learn more about other crops and how to tell whether they have / have not gone bad, read our guides on sweet potatoes and quinoa.

Frequently Asked Questions

how to tell if corn on cob is bad Frequently Asked Questions
What does corn mold look like?

One type of mold called diplodia manifests as thick masses of white mold on ears of corn. Typically, the mold starts growing at the base of the ear and works its way up. With the passage of time, the mold changes colors from white to gray to brown. The mold makes a sticky coating over the entire ear of corn that causes the kernels to adhere to the cornhusk.

What kind of corn mold is toxic?

All mold should be avoided. The most toxic of corn molds is Aspergillus flavus which contains a potent toxin called aflatoxin B1.

What happens if you eat corn mold?

The degree of illness you experience will depend on the type and amount of mold you have consumed. In some cases, you may experience aches, pains and/or fever, which will pass. In severe cases, you might develop chronic problems such as mood disorders, memory loss, constant headaches and/or problems with your central nervous system. Needless to say, it’s always best to avoid consuming mold!

Can exposure to moldy corn make you sick?

Breathing in spores from corn mold (e.g. in a barn where moldy dried corn is stored) can cause allergic reactions. With prolonged exposure, you may develop flu-like symptoms that don’t respond to treatment. rot.

If corn on the cob has a few mold spots, can they be cooked off?

It’s best to cut away any parts of corn on the cob or other veggies that may have developed a few small moldy spots. Then cook the vegetable thoroughly in boiling water at a minimum temperature of 212 °F for at least a full minute. When cooking corn on the cob, boil it for five minutes.

7 thoughts on “How To Tell If Corn On Cob Is Bad?”

  1. I bought some corn at the farmers market on Saturday, but when I got home there wasn’t room in the fridge. I put it in a cupboard to get it out of the way and meant to clear some space but I forgot about it… it’s now Wednesday, is it safe to eat or should I toss it? The silk looks a bit dark but I peeled a bit off the husk off and the kernels seem to look and smell fine…

    • Well, I hope you’ve eaten it or tossed it by now! It’s probably fine if it hasn’t gotten moldy or slimy. Remember, you will be boiling it to prepare it. That should kill off any lurking germs. Even so, if you are at all in doubt, you should toss it.

  2. We just harvested our sweet corn and noticed that must of the ears have red on the husks. When peeled the look fine. Is the corn safe to eat?

    • Corn gathered late in the growing season may have more photosynthetic sugar in the stalk than is needed. This sort of red pigment may also be a signal of plant stress caused by heat, a cold snap, drought or any number of plant stressors.

  3. Hi there,

    I just bought some corn on the cob that has some mold growing on the kernels by the silk. Should I throw away the entire cob or could I just cut off the ends since the rest of it doesn’t seem slimy or mushy (+ no bad smell)? Thanks!

    • Yes, you can just cut away mold. Be sure to trim a full inch away from the moldy spot. Cook the corn at boiling temperatures for at least a full minute before eating.


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