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Here’s Why Your Potato Turned Green

A group of potatoes has green spots.
FotoHelin/Shutterstock.com

It’s time to make dinner, and you reach for the potatoes only to discover green patches on the skin. How did this happen when they’re not even that old? It’s all part of how you store them.

Green potatoes happen due to exposure to sunlight and the vegetable’s natural processes.

When potatoes are in direct sunlight, the exposure speeds up the production of chlorophyll. The compound is what gives plants their green color and helps them feed themselves via the process of photosynthesis. Essentially, what you’re seeing is chlorophyll coloring the potato’s skin. While it might seem like that’s no big deal, and you should go right ahead with your french fries, you shouldn’t.

As chlorophyll increases another compound known as solanine has likely also increased. Solanine makes the potato taste bitter, and if you consume too many green potatoes you can get solanine poisoning which causes gastrointestinal upset, headache, and fever. However, if you’re able, you can cut around the green parts of the potato and still use the bits that haven’t begun to turn green. This way, your entire vegetable isn’t a total wash.

How do you prevent the greening? Potatoes should always be stored in a cool, dark space. If you keep them out on a counter, consider placing them in a pantry or cupboard instead. You can also purchase storage bins for them.

The next time you head to the grocery to buy potatoes, be sure you store them correctly and keep their expiration time in mind.

Shea Simmons Shea Simmons
Shea Simmons is an Atlanta-based writer who has written about everything from whether Crisco is a good moisturizer to how to KonMari your space. Her work has appeared in Bustle, My First Apartment, and Make It Grateful. Read Full Bio »
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