Potatoes. They sure last long, but they don’t last forever. Here’s everything you need to know about the humble spud.

We all love potatoes!

This humble root vegetable doesn’t cost much, fills you and everyone else at the table up, and tastes delicious however you prepare it—from creamy potato-leek soup to fluffy mashed potatoes to crispy French fries.

But not everyone knows that potatoes require special care during storage. And that, if not stored properly, they can develop toxins and make us sick. So let’s talk about how to store potatoes, how long they last, and how to tell if they’ve gone bad or not.

How to Store Potatoes

Store your potatoes in a cool and dark place away from direct sunlight, like in a kitchen drawer or on the shelving of your pantry, where they will keep for a few weeks to a few months. If the kitchen is too hot, keep the potatoes in an unheated basement or a root cellar, where it’s cooler.

Potatoes will last the longest if they can breathe, so store them in an open bag or a wicker basket. It’s okay to pile them on top of one another as long as the spuds are not packed too tightly and the ones on the bottom have room to breathe.

Another way to extend the shelf life of potatoes is not to wash them before storing them. If they are very dirty, Cedar Circle recommends letting the soil dry and then scraping it off with a vegetable brush. If you do end up rinsing them, pat them down thoroughly for storage.

What about when you cook them?

Cooked potatoes are a perishable food item that will go bad quickly if left out. They shouldn’t be kept at room temperature for more than 1-2 hours, and they must be refrigerated if you want them to last. Cooked potato leftovers will stay good in the fridge for up to 4 days.

This rule applies to all cooked potatoes, no matter the cooking method—boiling, stewing, sous-vide, mashing, frying, roasting, or grilling.

How Not to Store Potatoes

Now that we’ve covered the dos of storing potatoes, let’s talk about the don’ts.

Don’t keep potatoes on the windowsill. While it may be tempting to have the potatoes within reach, direct sunlight will cause their skin to turn green and make them taste bitter when they are cooked, according to Michigan State University Extension’s Diane Rellinger.

In How to Cook Everything, Mark Bittman writes that this bitterness is because the potatoes produce the mildly toxic alkaloid called solanine when they are exposed to sunlight.

Don’t refrigerate potatoes. The cold temperature in your fridge will turn the starches into sugars, making the potatoes a little too sweet and causing them to darken during cooking. Refrigerating potatoes, Harold McGee writes in Keys to Good Cooking, also makes them form a hard core that can’t be softened with cooking.

How Long Do Potatoes Last?

According to most sources, potatoes last anywhere from a few weeks to a few months, depending on how fresh they were when you bought them and whether you stored them properly.

WebMD reports that potatoes can stay fresh for several months when they are kept in a cool and dark place. Allrecipes‘ Melanie Fincher is more specific than that and says that whole, uncooked potatoes can last up to 2 months.

The key to making your potatoes last longer begins with your trip to the grocery store. If you choose them carefully and buy them fresh, they will stay fresh for a longer period of time. When choosing potatoes, select those that are firm, not shriveled or sprouting, and heavy for their size.

When the weather is hotter, and the temperature in your home is higher than usual, the potatoes won’t last as long as they normally do. This is the main reason why in summer when the temperature is 90°F (32°C) or above, potatoes sprout and rot quicker.

To prevent food waste, only buy as many potatoes as you can eat.

How to Tell If Potatoes Have Gone Bad

There are three ways for your potatoes to become inedible. If you want your home-cooked meals to be safe as you should, you need to watch out for each and every one of them.

Discoloration and sprouting:

Potatoes that have been stored in the sun or kept a little too long can turn green or start sprouting. Because they can contain toxins that can make you sick or even kill you, you should throw them away.

Rotting and spoilage:

Spoiled potatoes shouldn’t be eaten as they can contain molds and bacteria. If your potatoes have gone bad, they will be very soft and mushy, they will give off a bad smell, and sometimes they will leak a brown, watery liquid.

Prolonged storage when cooked:

Finally, if you cooked your potatoes and let them sit out for longer than 1-2 hours at room temperature or stored them for more than 3-4 days in the fridge, they may seem perfectly fine, and yet nevertheless be unsafe to eat!

This is because the bacteria that cause foodborne illness are not the same as the bacteria that cause spoilage; they don’t change the smell, taste, and appearance of your food.

Can You Eat Sprouted or Spoiled Potatoes?

This is something we’ve all done: you buy a big bag of potatoes, cook only a handful or two, then leave the rest to sit there for so long that you kind of forget about them.

A few weeks go by, and then, on a fine evening—just as everyone in the house gets excited about fries—you reach for the potatoes and realize they’re sprouted or, worse, rotten. Well, you’re not going to like the answer, but you’re almost always better off throwing out the potatoes and leaving the fries for another day.

Sprouted potatoes can contain high levels of two toxins, called solanine and chaconine, which can make you and your family members ill, says Diana M. Pei, Pharm. D. and Certified Specialist in Poison Information at Poison.org.

Potatoes gone bad can contain molds, toxins, and pathogenic bacteria that can cause food poisoning. If you think that the potatoes you have at hand are spoiled, don’t try to cook and eat them and throw them away instead.

Wrapping It Up

  • Store your potatoes in the drawer, pantry, basement, or root cellar—not on the windowsill and not in the fridge.
  • Uncooked potatoes last anywhere from a few weeks to a few months, depending on how fresh they were when you bought them and how well you stored them.
  • Cooked potatoes shouldn’t sit out on the counter or dinner table for more than 1-2 hours. Leftovers should be allowed to cool down and stored in the fridge, where they will keep for 3-4 days.
  • If your potatoes have turned green, formed sprouts, or show tell-tale signs of spoilage, err on the side of caution and throw them out.