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How to Tell if Sweet Potatoes Are Bad

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Foods like sweet potatoes have high water content, so their chances of spoiling are pretty high. But when anyone goes to the market to get groceries, they do not relish the idea of picking spoiled sweet potatoes. So, how can they tell the good ones from the bad ones? Let us find out.

How can you tell if your sweet potatoes have gone bad?

man holding freshly harvested sweet potatoes

A quick visual inspection of a sweet potato should reveal if it is bad or not. But sometimes, spoiled sweet potatoes may look like they are fresh. So, you may have to smell, taste, or examine the texture of sweet potatoes to verify their freshness.

Wondering what signs to look out for when checking if sweet potatoes are off? Wonder no more. Below, we do a thorough review of sweet potato spoilage. So, read and get the answers you are looking for.

Signs of Bad Sweet Potatoes

You can tell if sweet potatoes are bad through various methods, including the following:

The Taste

Sweet potatoes that have gone bad may have a bitter and acrid taste. If this is the case with your sweet potato, you should discard it at once.

Rotten Smell

Sweet potatoes do not usually have any strong odors. But when they spoil, they develop a rotten smell.

Sometimes it is difficult to figure out if you have a single rotten potato or a whole batch of them because of how strong the odor is.

But in this situation, cutting a piece of the potato and tasting it can help clear your doubts. If it tastes fine, then you don’t have to worry. But if it tastes unpleasant, discard it at once.

sweet potato in blue plate on wooden table

Original Skin Color Changes

Another way to tell if sweet potatoes are bad is by examining the skin for any color changes. Discolorations on the skin of sweet potatoes are a result of oxidation. And when you notice them, dispose of this sweet potato at once.

Your sweet potatoes are unsafe for consumption if they have these colors on their flesh:

  • Yellow
  • Purple
  • White
  • Black
  • Brown

Remember that some of the colors above are the regular color of some sweet potato varieties (such as purple sweet potatoes). You should only consider these colors as a sign of spoilage if they are unusual for that variety.


Fresh sweet potatoes are always firm and hard to the touch.

When your sweet potatoes feel soft and mushy, they have gone bad. 

Mushy sweet potatoes typically turn black or brown. But no matter the visual signs you see, dispose of them.

Sweet potatoes shrivel due to moisture loss. When this happens, do not consume them. Discard shriveled sweet potatoes at once.

Growing Roots

If you notice roots growing in the eyes of your sweet potato, it may be going bad. The sweet potato will still taste fine, but the quality of the sweet potato will drop as the root keeps growing.

When choosing sweet potatoes from your pantry, those with roots should be the first out.

Before cooking sweet potatoes with roots, trim the roots. Then peel and prepare as you would normally.

Mold or Black Rot

Another sign of spoilage in sweet potatoes is mold or black rot. Mold and black rot are both fungal diseases, and they cause the insides of sweet potatoes to rot.

When sweet potatoes get mold or black rot, they emit a foul odor similar to a rotten vegetable. But apart from that, you may notice signs like sprouting, shrinking, and crackling.                               

You can peel off small areas of mold from the sweet potato surface and cook what you have left. But if the moldy patches are big, discard the potato at once.

Black rot, on the other hand, makes the potatoes bitter and tasteless. So, never try to cook sweet potatoes with black rot.

Questions and Answers About Sweet Potatoes

What Do Bad Sweet Potatoes Look Like Inside?

Bad sweet potatoes may be drier than usual or full of holes inside. Sweet potatoes with dried insides have an off flavor and an irregular texture. They are generally stale and unappealing.

Sweet potatoes do not do well in storage areas that are too cold or too hot. So, when they are in a storage area that is too warm for them, they develop holes. When a sweet potato has holes, it loses its delicious flavor and texture. 

How Long Before a Sweet Potato Goes Bad?

Basket with sweet potatoes

The time it takes for a sweet potato to go bad depends on several factors like storage conditions, best by date, and preparation method.

Fresh sweet potatoes can last up to 3-5 weeks in a pantry at room temperature. When you store fresh sweet potatoes in a fridge, they can last around 2-3 months before they go bad.

Cut sweet potatoes can last up to a week in the fridge if you store them properly. But ensure you use them within a day or two for optimal quality.

Cooked sweet potatoes can last up to 3-5 days in the fridge before they go bad. To extend their shelf life, store them in the freezer and ensure you wrap them properly.

State of the PotatoStorage ConditionShelf Life
FreshRoom temperature (Pantry)3-5 weeks
FreshFridge2-3 months
CutFridgeUp to 7 days
CookedFridge3-5 days

Are Sweet Potatoes Bad if They Have White Inside?

Sweet potatoes are not bad if they have white inside. So, when you peel your sweet potato and notice it has white flesh with white exudate or spots, you may be holding a yam. Some supermarkets mislabel yams and sweet potatoes, possibly as a form of marketing. But these vegetables are totally different.

Yams usually have brown skins with purple or white flesh, while sweet potatoes have orange flesh. Additionally, yams have a drier texture and are not as sweet as sweet potatoes.

The white spots you see in sliced sweet potatoes are sugar and starch bursting through the flesh. They are harmless, and you can just rinse them off.

If Sweet Potatoes Float, Are They Bad?

Sweet potatoes floating is not always a sign of spoilage. Sometimes a floating sweet potato is still safe to eat; it may just be on the older side.

If the sweet potatoes float and you do not see any signs of spoilage, the potato is still safe to eat.

sweet potatoes in a box


Spoiled sweet potatoes may show skin discoloration, have a rotten smell, mold, a sour taste, wrinkled surfaces, and other signs.

You may not notice all of these signs when examining your sweet potato. So, always ensure to employ all your senses.