How to Tell If Potatoes Are Bad (and How to Keep Them Fresh in the First Place)

Whoever dubbed it the “humble” potato forgot how versatile, not to mention delicious,the spud can be. And when you consider that potatoes can last in storage for months (months!), they’re basically a pantry hero. Still, if you bought a bag weeks ago and now you think they might be past their prime, it can be a little murky. Here’s how to tell if potatoes are bad, plus how to keep them fresh in the first place.

How to Tell if Potatoes Are Bad

It’s safe to say that if your potatoes growing any amount of mold, they’re no longer safe to eat. (And no, you can’t just cut the mold off, because the tiny invisible spores could already be growing elsewhere in the tuber.)
But what if they’re just a little soft, or have a few sprouts? As long as the potatoes are still mostly firm, they’re fine to cook. Potatoes are 80 percent water, so softness is usually just a sign of dehydration. But if they’re extremely mushy or shriveled, do not pass go.
Likewise, small sprouts can be removed with a vegetable peeler or knife. Long or large sprouts are a sign that the potato is probably past its prime and should be tossed. (You could technically plant the sprouts, if you wanted.)

Can you eat potatoes that are green?

Unlike green eggs and ham, green potatoes aren’t so nice. While the color itself is just a harmless increase in chlorophyll, it’s also a sign of something more sinister: According to the USDA, when a spud turns green, there’s usually an increase in a toxic compound called solanine, which can cause headaches, nausea and neurological problems in large amounts. But the USDA also says that you can safely “just peel the skins, shoots and any green color” because that is where the solanines concentrate. If a potato is entirely green, you should toss it; otherwise just trim and proceed. The green parts taste bitter, so if your tater tastes bitter, don’t eat it.

How to keep your potatoes fresher, longer:

When stored properly, your tubers can last for weeks or even months. Here, a few key pointers:

• At the grocery store, look for unblemished potatoes with no cuts or bruises, smooth skin and shallow eyes (those little divots on the skin)
• If the potatoes came in a plastic retail bag, transfer them to a basket so they can breathe
• Don’t wash the potatoes until you’re ready to cook with them. Dirt protects the potatoes from premature spoiling, and storing moist potatoes could lead to mold
• Store potatoes in cool but not cold temperatures; between 45°F and 55°F is ideal. Store them too cold (i.e., your fridge) and the starches will turn to sugar, affecting taste and texture. Temperatures higher than 55°F will accelerate dehydration
• Potatoes will turn green from too much sunlight, so keep them somewhere dark and cool (like a cellar)
• Don’t store potatoes and onions together. Onions emit a gas that will cause the potatoes to spoil faster