There are some ways to tell if a potato is bad. Potatoes that have sprouts coming out of them, or potatoes that are soft or discolored are usually bad.
There’s also an easy way to check the potatoes with your eyes. If there are any sprouts on the potatoes, these can be seen by looking closely at the surface of the potato. If you want to check a potato for discoloration, just cut it in half and look at the color inside.
If the color is a greenish-yellow, this potato is bad. If it’s a light yellow, the potato is good to be cooked and eaten.
-> Don’t keep potatoes in very warm temperatures for too long, because they can rot.
-> Be aware that if you want to store your potatoes in the freezer so you can use them for other purposes at a later time, don’t keep them in the freezer for more than two months.
Keep potatoes away from heat and moisture to avoid molding or rotting. Store them in a cool place with low humidity. A kitchen pantry is generally a good place to store your potatoes until you cook them.
So this is how to tell if a Potato is bad or rotten.