Beware of Toxins: When You Should Definitely Peel Potatoes

If you find green spots or sprouts on your potatoes, you need to be careful. Here's why and what you should do to make sure your potatoes are safe to eat.

While you can usually cut out small green spots on potatoes, you should be cautious if your potato has sprouted. Here's what you need to know.

If stored at temperatures above twelve degrees Celsius, potato tubers (the name given for the sprouting part), often sprout prematurely. Like the green spots caused by light exposure, sprouts also contain solanine and other bitter substances.

Solanine is a natural defense of the tuber against pests and fungal infestation. This substance is found in the skin, in unripe or green potatoes, and in the bases of the sprouts.

According to experts, even small amounts of solanine are toxic to humans. Symptoms of poisoning, such as headaches, diarrhea, and vomiting, can occur if only one milligram of solanine per kilogram of body weight is consumed.

Tubers with sprouts longer than three centimeters should no longer be used for food. To avoid sprouting, you should buy only small quantities of potatoes to prevent long storage periods and thus stop the increase of solanine content. If potatoes have only a few or short sprouts, you can consume them without any problems. But what about the skin?

Can You Eat Potato Skins?

According to the State Center for Nutrition in Germany, you should generally eat potatoes without the skin. However, you can eat the skin of fresh, ripe (organic) potatoes.

You should peel potatoes if they have the following characteristics to avoid ingesting toxins like solanine, chaconine, and pesticides:

• The skin has many green spots and has already started to sprout.
• The potatoes have damage on the skin.
• The potatoes are not fresh and were not stored properly.
• The potatoes were imported from abroad: Foreign tubers may have a higher solanine content than is allowed for domestic products.

When Shouldn't You Eat the Skin?

If you are pregnant or have children, you should peel potatoes before cooking. Due to lower body weight, even small amounts of solanine can lead to symptoms of poisoning.

If you peel potatoes after cooking, you should discard the cooking water, as residues of toxins can leach into the water. In the case of peeled potatoes, the water can be reused in various ways.