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How to Tell if Corn on the Cob Is Bad?

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What’s better than juicy, sweet corn on the cob? It’s tough to beat, but buying good corn isn’t always easy. Everyone wants to avoid buying bad corn. Thankfully, there are ways to tell whether your corn is still fresh or not.

How do you know whether the corn you buy, cook, and eat is good?

Bad corn on the cob will usually have missing kernels, darker areas on the corn, and other obvious signs of rot. In addition, bad corn will smell sour or rancid. It will also turn mushy if you leave it in the fridge for too many days. Some corn also develops what people describe as a slimy film when it goes bad, making it unpleasant to eat.

Fresh corn on the cob on wooden table

Of course, no one wants to eat bad corn on the cob. So here are some things to help you know how to tell if corn on the cob is bad to guarantee you buy and make the best corn available for you, your family, or guests who come over for dinner.

Cook Your Corn Soon After You Buy It

Corn has a fairly long shelf life, especially compared to a lot of leafy produce next to it in the produce section of your local grocery store. Keeping it in the fridge will usually make it last for a week after you buy it. If you leave it on the counter, it will be good for about three or four days.

steaming hot cooked corn on wooden rustic board

Instead of leaving things for too long, you should cook your corn quickly after you buy it to ensure you eat it when it is at its freshest. The longer you leave it, the more it will dry out and lose its flavor.

On the other hand, eating a delicious piece of corn on the cob is a wonderful summer treat, particularly when corn is in peak season.

So, only buy corn on the cob when you can cook it the day you buy it or soon after that. You’ll notice a significant difference in how it tastes compared to leaving it in the fridge for a week before you eat it.

Three corn on the cob on shelf of open empty refrigerator

How Long Will Corn on the Cob Last in the Refrigerator?

Refrigerating your corn on the cob will make it last longer than keeping it out on the countertop at room temperature. Typically, you can expect about a week or so out of your corn at cooler temperatures.

Shucked corn on the cob goes bad a bit quicker than corn that is not shucked because of the protection from air, and the layers help trap moisture inside to keep it from escaping and drying out the corn.

The same goes for cooked corn on the cob. After you cook it, you can keep it in the fridge for about a week. To keep it longer, wrap it in plastic or keep the corn on the cob in an air-tight container to keep it juicy and stop the decaying process.

Three moldy corn on white background

What Does Corn Look Like When It Starts to Go Bad?

The easiest sign of corn going bad is when it starts to dry out. Corn kernels will become tougher, and you may even see some indents, indicating they are losing their firmness and that the water content inside is escaping.

You’ll also likely start to see physical signs of rot, like white ear rot or red spots starting to appear on the ear. When your corn on the cob starts to turn a color different from the usual before or after you cook it, it’s time to throw it away.

Another indication your corn on the cob is bad is if it starts to smell sour. The corn should smell like fresh corn. Any musty or sour smell is a big red flag.

Finally, fresh corn should have firm kernels with juicy interiors. As corn on the cob dries, you’ll get less juice. The kernels become hard and stale. Brown kernels aren’t usually that big of a deal. You can cut off the section of the cob with the brown or gray grains and keep eating the rest.

Spoiled corn cob on the field in sunny hot summer day

What Does Bad Corn Taste Like?

An ideal corn should taste like the fresh corn on the cob you remember from your childhood and all those countless weekend barbeques you’ve had before. Anything different is reason enough to toss it in the garbage can and grab a new piece of corn on the cob.

Sometimes, bad corn on the cob will taste exactly as it smells. It will sometimes have a tangy or sour flavor that you won’t want to keep eating, no matter how much salt or butter you put on it.

Closeup view of ripe corn cobs in box with sack cloth on wooden surface

How Long Does It Take for Corn on the Cob to Go Bad?

As mentioned, corn on the cob will go bad after about a week. Also, raw corn will start to dry out after three or four days if kept at room temperature. On the other hand, you’ll get a full week of fresh corn if you keep it in the fridge.

Once you cook it, you can eat it as leftovers for up to about a week after. So, in total, you may get up to two weeks from the time you buy it to the time you eat it.

When you’re buying corn on the cob at the grocery store or a farmer’s market, you should inspect the corn to ensure you’re not buying any ears with obvious mold or rot. Also, check to see if you can gauge the moisture level in the kernels because it’s a good indication of how fresh the corn is and how long it will last.


Fresh corn on the cob is delicious. However, knowing how long you can preserve it and how to avoid rotten corn on the cob will help prevent you from getting sick or wasting money at the grocery store.

When stored properly before and after you cook the corn, you can get plenty of time out of it to enjoy with family and friends or as leftovers for days after your barbeque.