Is a green peel on potato rotten?

No, a green peel on a potato is not necessarily rotten. The green color is caused by a compound called chlorophyll, which is produced when potatoes are exposed to light. While green potatoes may have a slightly bitter taste, they are still safe to eat as long as they are cooked properly. However, it is important to note that potatoes that have turned green should be used as soon as possible, as they may start to develop harmful bacteria if they are stored for too long.