Sweet potatoes are highly nutritious vegetables enjoyed year round in many households. They contain high amounts of vitamins A and C, along with beta-carotene and no fat or cholesterol. Another positive attribute of the sweet potato is its ability to stay fresh for up to a month if stored in a cool, dry place. However, sweet potatoes can go bad quickly if not properly stored, and there are several tell tale signs of a spoiled sweet potato.
Examine the sweet potato for any signs of decay. Decay in sweet potatoes can be seen as dark brown spots or small craters on the surface. Decayed spots can be cut away from the rest of the potato, but the bitter taste may linger in the rest of the vegetable.
Run your fingers over the skin of the sweet potato. If the skin is highly wrinkled and dehydrated, then the sweet potato may be going bad.
Look for any small sprouts or roots coming from the sweet potato. Freshly growing roots will be slightly lighter than old roots which are harmless. Fresh roots are a sign that your sweet potato is spoiled.
Cut into the sweet potato and look for any dark brown spots on the inside of the flesh. These spots can sometimes be difficult to spot on the outside. If they are on the inside, your sweet potato is bad.