How to Tell If Sweet Potatoes Are Bad
Quick answer
Bad sweet potatoes get soft, mushy, and wet, with dark sunken spots, mold, or a sour, fermented smell. A firm sweet potato with a few sprouts or a small blemish is usually fine after trimming.
Signs Sweet Potatoes have gone bad
- Mushy, collapsing flesh. A sweet potato should be solid. If one feels soft or squishy in places, or caves in when pressed, it’s rotting.
- Dark, sunken, or wet spots on the skin. Shallow spots can be cut away if the flesh underneath is bright and firm. Wide, wet, or deep black sunken areas mean it’s time to toss.
- White, gray, or green mold. Fuzzy growth, especially around the ends or cracks, means spoilage. Don’t cut around it; throw the whole thing away.
- Sour or alcohol-like smell. Fresh ones smell faintly earthy. A fermented, boozy, or rotten odor means the inside has broken down.
- Dry, hard, brown or black interior. Cut it open. Streaks of dry, corky, or black tissue throughout mean it’s past its prime. Tiny trimmed areas are fine, but widespread discoloration is a toss.
- Bitter taste after cooking. A very bitter or chemical taste can mean damage or rot. Spit it out and discard the rest of the batch you cooked it with if it’s clearly off.
Looks weird, but it's fine
- Short sprouts. Sweet potatoes sprout when stored warm. Snap them off. As long as the potato is firm, it’s safe to eat.
- Dark sticky spots of sap on the cut end. Sweet potatoes ooze a dark, sugary sap. It’s harmless; trim a thin slice if it bothers you.
- Thin white or tan lines inside, or dark flecks in the skin. Fibrous streaks and small skin blemishes are normal and don’t affect safety.
How long do Sweet Potatoes last?
| Where | How long | Note |
|---|---|---|
| Pantry (cool, dark) | 3–5 weeks | whole, uncooked |
| Fridge | 3–5 days | cooked |
| Freezer | 10–12 months | cooked and mashed or cubed |
How to store them
- Keep raw sweet potatoes in a cool, dark, airy place around 55–60°F if you can. A basket in a pantry works well.
- Don’t refrigerate raw ones. The cold gives them a hard core and off flavor.
- Leave them unwashed and unwrapped until you’re ready to cook, and use any bruised ones first.
Use it up before it turns
Frequently asked questions
Can you eat a sweet potato with sprouts?
Yes, if it’s still firm. Break off the sprouts and cut away any soft areas. If the sweet potato is shriveled or mushy, skip it.
Is it safe to eat a sweet potato with black spots?
Small shallow spots can be trimmed away. If the spots go deep, feel wet, or the inside is black and hard, discard it.
Why does my sweet potato smell bad?
A sour or fermented smell means bacteria or mold have broken down the flesh from the inside. Throw it away, even if it looks decent outside.
More food freshness guides
General guidance based on USDA FoodKeeper. Storage times are estimates and conditions vary. When in doubt, throw it out.