Quick Answer
Yes, uncooked corn on the cob can go bad. Like most fresh vegetables, corn is perishable and has a limited shelf life. Properly stored, uncooked corn on the cob will usually last 3-5 days in the refrigerator before quality starts to decline. Signs that corn has gone bad include dried, shrivelled kernels, brown spotting, mould growth, and an unpleasant sour smell. Freezing is the best way to extend the shelf life of fresh corn for several months.
How Long Does Uncooked Corn on the Cob Last?
Freshly picked corn on the cob will last approximately:
| Storage Method | Shelf Life |
|---|---|
| Room temperature | 1-2 days |
| Refrigerator | 3-5 days |
| Freezer | 8-12 months |
The exact shelf life of uncooked corn depends on a variety of factors like harvest time, storage temperature, and handling. Corn that is fresher will generally last a little longer. Proper storage helps extend shelf life.
Shelf Life of Corn on the Cob at Room Temperature
At room temperature, corn on the cob will only stay fresh for about 1-2 days before quality starts to decline. Warm temperatures allow the natural enzymatic processes in corn to accelerate and cause it to mature and dry out more quickly. Leaving corn out on the countertop or dining table is not recommended.
For best quality, fresh corn should be refrigerated as soon as possible after harvest or purchasing. However, brief storage at room temperature up to 2 days is acceptable if necessary.
Shelf Life of Corn on the Cob in the Refrigerator
Proper refrigeration at 40°F (4°C) or below will preserve freshness and extend the shelf life of uncooked corn to around 3-5 days. The cold temperature significantly slows down enzymatic activity and mold growth.
Corn should be placed in the high humidity environment of the refrigerator produce drawer. You can wrap the husked ears of corn in a damp paper towel or reusable produce bag before refrigerating, which will help retain moisture. Avoid washing the corn prior to storage as this can hasten spoilage.
For whole corn with the husk on, simply store the ears in the fridge as is. The husk protects the kernels and inhibits moisture loss.
Freezing Corn on the Cob
Freezing is the best way to prolong the shelf life of fresh corn for 8-12 months. Blanching prior to freezing helps stop enzymatic processes that lead to loss of flavor and texture.
To freeze:
– Husk corn and remove silk strands.
– Bring a large pot of water to boiling. Blanch ears for 3-5 minutes depending on thickness.
– Transfer to ice bath to stop cooking process. Drain and pat dry.
– Cut kernels off cob or freeze whole.
– Place ears or kernels in freezer bags or airtight containers, pressing out excess air.
– Seal and label with date.
Properly frozen corn will retain its texture and sweet flavor when thawed and cooked.
How to Tell if Corn on the Cob Has Gone Bad
Here are some signs that corn on the cob has spoiled and is unsafe to eat:
– Kernels appear dried, shriveled and indented.
– Brown spots or lesions on kernels.
– White, blue, grey or black fuzzy mold.
– Soft, watery texture (for fresh corn).
– Slimy texture (for frozen corn).
– Unpleasant sour or fermented odor.
Appearance and Texture
Fresh, good quality corn kernels will be plump, firm and translucent. Avoid corn with kernels that are starting to dimple, shrivel or take on a glassy, dried out appearance.
Significant wrinkling, soft or mushy spots indicate the corn is overripe and past its prime. If the husk looks dried out and deflated, this reflects the condition of the corn inside.
With spoiled frozen corn, the kernels will turn mushy and take on a slimy texture when thawed.
Discoloration
Look for brown, grey or black discolored spots on the individual kernels, which signal decay. Corn smut is a fungal disease that causes swollen, spore-filled galls on the corn. Do not eat ears with signs of corn smut.
Icing and old, freezer burned corn may have white or yellow discolored kernels. This corn will still be safe to eat but the texture and flavor will be inferior.
Mold Growth
The development of mold on corn is a clear warning sign it has spoiled and should be discarded. You may see fuzzy white, blue, green or black mold growing on the husk, silk strands or directly on the kernels. This can occur with refrigerated corn after several days or if frozen corn has been thawed and left too long. Any level mold is unsafe to consume.
Unpleasant Odors
Fresh corn has a sweet, grassy aroma. Discard corn that smells unpleasantly sour, stale, fermented or funky. Off-odors indicate spoilage bacteria are present. The smell test is the quickest way to identify bad corn.
What Causes Corn on the Cob to Spoil?
Corn has a naturally high moisture content, which makes it prone to spoilage from enzymes, bacteria and mold. Several factors contribute to the degradation of quality in fresh corn:
Conversion of Sugars
Corn kernels contain natural sugars that convert to starch after harvest. This process accelerates at higher temperatures, causing the corn to lose sweetness and become tough and starchy. Refrigeration slows this conversion.
Loss of Moisture
As corn matures, moisture evaporates from the kernels, making them dry out. Leaving corn husked speeds moisture loss.
Enzyme Activity
Enzymes break down the cell structure. Heat from cooking destroys enzymes, but they continue to develop in fresh raw corn after picking.
Microbial Growth
Yeasts, molds and bacteria can grow on corn, causing discoloration, sliminess and off-odors. This occurs quickest on damaged, bruised kernels.
Freezer Burn
Improperly frozen corn can suffer freezer damage, resulting in dried out, shriveled kernels.
How to Store Corn on the Cob Properly
Proper storage methods help keep uncooked corn on the cob fresh longer:
– Refrigerate corn as soon as possible, within 2 hours of harvesting or purchasing. Leave husked if possible.
– If husking corn, be sure to remove all silk strands from the ears as these accelerate spoilage.
– Place corn in perforated plastic produce bag or damp paper towels before refrigerating. Do not wash prior to storage.
– Keep corn towards the back of the produce drawer away from ethylene-producing fruits.
– Do not store corn on the cob at room temperature more than 2 days.
– To freeze: blanch ears 3-5 minutes, then chill in ice bath before cutting kernels off cob.
– Freeze corn with kernels sealed in airtight containers or resealable plastic freezer bags.
How to Use Up Corn on the Cob Before It Goes Bad
To avoid waste, properly store corn for the short term and cook it soon within 3-5 days. Here are some delicious ways to use up fresh corn on the cob:
– Boil or grill it and eat immediately with seasoning and butter.
– Cut kernels off the cob and sauté with garlic, peppers and onion for a quick sautéed veggie side.
– Bake corn on the cob wrapped in foil on the grill or in the oven.
– Cut kernels off and mix into cornbread, waffles or pancake batter.
– Simmer husked ears in chicken or vegetable stock for an easy soup.
– Use corn kernels in relish, salsa, salad or slaw.
– Cut corn off cob and blanch then freeze to store longer term.
With proper storage and usage, you can enjoy sweet summer corn on the cob to the last bite. Monitor closely for any signs of spoilage and discard corn at the first indication it has gone bad.
Frequently Asked Questions
Can you get sick from eating spoiled corn?
Yes, consuming spoiled, rotten corn can make you sick. Moldy corn may contain mycotoxins that cause illness. Bacteria like Salmonella, Listeria, and E. coli can also grow on spoiled corn and lead to food poisoning when ingested. Symptoms include nausea, vomiting, stomach cramps, and diarrhea.
Can you cook and eat corn that looks bad?
No, it is unsafe to try to cook and eat corn that has visible mold, unpleasant odors or other signs of spoilage. These indicate potentially harmful bacteria are already present, and cooking cannot get rid of the associated toxins. Bad corn should always be discarded.
Is it OK to cut off bad parts of corn and eat the rest?
It’s best not to attempt salvaging parts of spoiled corn, since bacteria and toxins likely have spread from the visibly rotten areas. Any corn that has gone bad is risky to consume and the entire ear or batch should be thrown out. Don’t take chances with partially spoiled corn.
How can you tell if frozen corn has gone bad?
Signs frozen corn has spoiled include an off odor when thawed, unusual softness or mushiness, and any mold development. Discard corn that exhibits foul odors or textural changes instead of trying to cook it. Freezer burned kernels are still safe to eat but will be lower quality.
Can you refreeze corn after thawing?
Previously frozen corn should not be refrozen after it has been fully thawed. Partial thawing is acceptable. Fully thawed corn has a higher risk of bacterial growth, so it must be cooked immediately or discarded if not used right away after thawing.
Summary
Corn on the cob has a limited shelf life. Kept at room temperature, it will only stay fresh 1-2 days. Refrigeration extends the shelf life up to 3-5 days. For long term storage, corn can be frozen for 8-12 months.
Signs corn has spoiled include dried, wrinkled kernels, mold, brown spots, slimy or mushy texture, and off smells. These indicate possible pathogenic bacteria or toxins, making the corn unsafe to eat. Prevention is key – eat fresh corn soon and store properly in the refrigerator or freezer to extend its shelf life. Discard corn immediately if you see any signs it has gone bad. With proper handling, you can enjoy sweet corn until the last kernel.
