How To Know If A Sweet Potato Has Gone Bad

Sweet potatoes are nutrient-rich root vegetables that nourish your body in lots of ways. Also, they come in an array of shapes, sizes, and colors. Since they contain high levels of antioxidants and fiber, they keep free radicals at bay whilst promoting a healthy brain and gut.

As well as being good for you, sweet potatoes are also a delicious addition to any meal. I started eating them because I’d been told they were a healthier alternative to regular potatoes but the truth is, I think they taste better too!

Alas, such is life that all good things have a downside. Like any fresh food, sweet potatoes do go bad over time.

In this article I’ll explain how you can know if a sweet potato has gone bad. I’ll also show you how to properly store them to keep them safe, as well as how to extend their shelf life.

What Happens if You Eat a Bad Sweet Potato?

Depending on the amount of moisture in your kitchen cupboard or pantry, they can last for a week or so. However as the days go by they will start to shrivel up and lose their flavor.

In the worst case scenario, they can be exposed to high moisture levels and start to rot or develop aflatoxins. Aflatoxins are bad news and can cause some serious health conditions. They’re produced by certain types of fungus, which thrive in moist environments.

Because of this it’s really important that you store sweet potatoes in a dry place.

Outside of the potential for developing aflatoxins, bad sweet potatoes can also harbor mold and potentially harmful bacteria – both of which can cause symptoms of food poisoning.

How Long Before a Sweet Potato Goes Bad?

How long sweet potatoes last depends on how you store them. If stored in the pantry at normal room temperature, expect them to last for 3-5 weeks. In the fridge, they can keep for up to 3 months, whilst in the freezer they can last as long as 12 months.

Storage MethodHow Long Will It Last?
Pantry/Kitchen cupboard at room temperature3-5 weeks
FridgeUp to 3 months
Freezer0-12 months

When storing your sweet potatoes, I should stress again the importance of ensuring that you keep them in a dry environment.

If this isn’t possible, either eat them quickly or throw them out. This is because sweet potato tubers can produce aflatoxins within five days if stored in wet conditions.

What Are Signs That Let You Know a Sweet Potato Has Gone Bad?

So how can you spot the signs of a sweet potato on the turn?

There are 3 clear signs you should look for before cooking:

  • Color Change
  • Visibile Mold
  • Bad Odor

Color Change

Good sweet potatoes should either have a white, purple, or red color. However, when they start to turn brown or black, it’s a sign that they’ve gone bad.

When sweet potatoes begin to spoil, they will turn from brown to black and become mushy. They darken as a result of phenols or chlorogenic acid. Once the chlorogenic acid and iron in the sweet potato combine, rotting is inevitable. The process can be escalated by the presence of oxygen from the atmosphere and water.

Visible Mold

If you see any fuzzy spots on the inside or outside of a sweet potato, throw it out. Even if you scrape the visibile mold away, the stuff you can’t see can be very harmful.

Bad Odor

Aside from showing up in a way you can see, the growth of mold can also produce an unpleasant odor.

Before cooking, follow the tried-and-true ‘sniff test’. You’ll know a sweet potato has gone bad if there is a strong ‘off’ smell. This can be caused by microbes such as mold, bacteria, and yeast.

Is a Sweet Potato Bad if it has White Spots?

Sometimes when you chop a sweet potato, you may notice white spots of liquid forming on it. This can even happen quite literally as you watch!

Fortunately, this isn’t something to worry about. White spots are not a sign that a sweet potato has gone bad.

The white spots are made from a combination of starch and water, sometimes referred to as vegetable sap. It’s completely harmless, but can be washed off before cooking if you prefer.

How to Store Sweet Potatoes?

Due to the risks of aflatoxin and mold poisoning, the proper handling and storage of sweet potatoes after harvesting cannot be overemphasized. If you want the sweet potatoes to stay fresh, you must adhere to the recommended post-harvest practices.

First it’s wise to sort them immediately after harvesting. Some of the sweet potatoes will be cut unintentionally during harvesting. The lack of a protective cover will expose them to bacteria, yeast, and fungi. If you want to protect them from microbial decay, be sure to get rid of the cut pieces.

The high perishability of sweet potatoes calls for special storage methods to improve the shelf life. Avoid storing them in large heaps that provide the perfect breeding grounds for the sweet potato weevil (Cylas spp). Instead, store them in the racks in your pantry.

You must wash and dry them before storage. If you don’t remove the soil that holds onto them, you will encourage decay since the soil has moisture. A bumper sweet potato harvest that cannot fit in the pantry can be stored in the barn. However, you need to cover the sweet potatoes with hay to keep them dry at all times.

It’s important to cure sweet potatoes after harvest. After digging, wash and allow them to dry for two hours. Don’t expose the sweet potatoes to cold night temperatures or moisture that can damage them. Store them in a well-ventilated room for two weeks. Never store raw sweet potatoes in the refrigerator.

Can You Freeze Sweet Potatoes?

If you want to store cooked sweet potatoes for six months, you will have to freeze them. Keep the freezer between zero and five degrees for the best results. You can either roast or boil them before squeezing lemon to prevent discoloration.

How to Freeze Sweet Potatoes

Before freezing, store them in airtight containers to prevent moisture damage. Remember that cutting or slicing the sweet potatoes before freezing will reduce their shelf life.

If you are planning to store sweet potatoes for about one year, you will have to bake them first.

Bake whole sweet potatoes for one hour and let them cool for one hour. Wrap them carefully in foil and place them in the freezer. Whenever you want to cook the sweet potatoes, just remove the foil, start by cutting them into pieces