Signs That a Potato Is Bad: Raw & Cooked

Written by Olivia Choong | Edited by Hannah Madden

Last Updated: October 15, 2024 Fact Checked

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Planning to make potatoes tonight with dinner? Yum! But what’s that smell? And why do the potatoes look so… wrinkled? Discerning a spoiled potato from a potato that’s good to eat can be a little tough, especially if you don’t know what you’re looking for. That’s why in this article, we’ll give you all the signs to watch for to tell if a raw or cooked potato is bad. We’ll also share handy tips about eating sprouted or green potatoes, as well as how long you can keep potatoes in the fridge or freezer.

This article is based on an interview with our plant and gardening specialist, Olivia Choong, owner of The Tender Gardener. Check out the full interview here.

Things You Should Know

To tell if a raw potato is bad, look for a soft texture, wrinkled skin, or a bad smell.
To tell if cooked potatoes are bad, check for a strong foul odor or visible mold.
If your potato has sprouted, you can still eat it. Just cut the sprouts off and you’re good to go.
You can eat green potatoes if they’re only slightly green. If they are very green or the entire potato is green-colored, throw the potatoes out.

Section 1 of 7:

How to Tell If a Whole Raw Potato Is Bad

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Soft or mushy texture Fresh potatoes are firm and not tender to the touch. If you pick up a potato and it feels soft or mushy inside, that likely means that it’s rotten.
- This is especially true for sweet potatoes. Since sweet potatoes have a high moisture content, when they go bad, they get mushy very quickly.^{[1]
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- If the potato only has a small soft spot but the rest is firm, cut off the soft area before eating the rest.
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Wrinkled skin When you buy potatoes, you’ll notice that the skin is tight and doesn’t move much. When a potato gets wrinkled skin, that means that it’s gone bad.
- You might also notice dark spots or sagging, both of which indicate the potato has gone bad.
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Fresh potatoes smell earthy, nutty, and starchy but they don’t smell bad. If you take a whiff of the potato and it smells rotten or like mold, it’s time to throw that potato out.^{[2]
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Section 2 of 7:

How to Tell If Cooked Potatoes Are Bad

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It’s a little bit harder to tell when cooked potatoes have gone bad, but the number 1 indicator is their smell. If you grab your cooked potatoes and they smell sour or rotten, they are not good to eat anymore.^{[3]
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Visible mold definitely means your potatoes have gone bad. Look for brown, black, or green spots on the cooked potatoes to know they’re past their prime.^{[4]
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Food Safety and Inspection Service of the USDA
Food safety information provided by the U.S. Department of Agriculture.

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For mashed potatoes in particular, you can tell that they’re bad when the liquid starts to separate from the solids. If you go to eat your mashed potatoes and there’s a layer of liquid on top, they’re unfortunately spoiled.^{[5]
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Section 3 of 7:

Can you eat a sprouted potato?

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Yes, you can eat a potato that has just sprouted if you cut the sprouts off. Sprouting potatoes aren’t rotten, but they might go bad in a couple of days. If you have a sprouted potato that you still want to eat, just use a knife or a peeler to cut the sprouts off.^{[6]
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Research source} However, if your potato has very long sprouts, the potato likely has very little nutritional value left, and you’re better off throwing it away.
- As the potato sprouts, it pulls nutrients out from the potato itself. This means that eating a sprouted potato won’t be as nutritious as eating a fresh one.
- Cutting the sprouts off first is essential. Potato sprouts are mildly toxic, and can make you sick.

Section 4 of 7:

Can you eat a green potato?

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Yes, you can eat a green potato if it just recently turned green. The green color that potatoes sometimes get happens when they’re exposed to light. If you only notice a slight tinge of green in 1 area, cut the green parts off and enjoy your potato.^{[7]
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- If the potato is bright green or green all over, don’t eat it. The solanine inside of the potato that causes the green color can be toxic in large quantities, and it doesn’t taste very good, either.^{[8]
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- Never feed green potatoes to small children. Since they are smaller than adults, kids have a higher chance of developing a bad reaction to the solanine in the potato.^{[9]
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Section 5 of 7:

What happens if you eat bad potatoes?

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Eating bad cooked potatoes may give you food poisoning. Cooked potatoes can collect bacteria that’s dangerous to ingest after just a couple of days. If you eat a cooked potato that’s too old, you may experience fever, nausea, vomiting, or diarrhea. Thankfully, food poisoning usually subsides after a couple of days.^{[10]
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Centers for Disease Control and Prevention
Main public health institute for the US, run by the Dept. of Health and Human Services

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- If you cannot keep liquids down or you’re still having symptoms after more than 3 to 4 days, go to the doctor.
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Eating very green potatoes or potato sprouts can give you stomach problems. Since green potatoes and potato sprouts both contain a mild toxin, eating them could give you symptoms like stomach pain, nausea, vomiting, or diarrhea. Fortunately, these symptoms usually go away on their own in a couple of days.^{[11]
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U.S. National Capital Poison Center
Independent poison control center providing resources to prevent poisonings and save lives

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- If your symptoms persist for longer than a few days or you can’t hold down liquids, contact your doctor.

Section 6 of 7:

How to Store Raw Potatoes

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Keep whole, raw potatoes in a breathable bag. Go for a basket, a crate, or a paper bag to make sure the potatoes have enough air flow. Stay away from anything airtight, as that will make your potatoes go bad much faster.^{[12]
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- If you’re storing raw cut potatoes, keep them in a bowl of cold water and put them in the fridge. Use your potatoes within 24 hours.
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Store potatoes in a cool, dry place. Pick a spot that stays around 50 °F (10 °C). Your pantry, basement, or cellar are all great options for storing raw potatoes.^{[13]
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Research source} Don’t store raw potatoes in the fridge, as the cold temperatures can alter the flavor of the potatoes, making them sweeter.
- Avoid storing your potatoes near onions or apples. Onions and apples emit ethylene gas, which can make a potato sprout faster.
- Don’t wash your potatoes before you store them, either. The excess moisture can make your potatoes go bad faster.
Most raw potatoes will stay good for about 8 weeks—after that, you may notice sprouting or signs of rotting. Keep an eye on your potatoes and plan to eat them before they go bad.^{[14]
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Section 7 of 7:

How to Store Cooked Potatoes

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Grab a sealable bag or a container with a lid and throw your cooked potatoes inside. Keeping air out will help your cooked potatoes stay fresh for longer.^{[15]
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Cooked potatoes don’t last long. Plan to eat them within the next couple of days, and check for mold or a bad odor before you dive in.^{[16]
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Want to store your potatoes for longer? Throw them in the freezer, and make sure to add a label with today’s date.^{[17]
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