About Green Potatoes

Green = vegetables = good, right?

Not when it comes to potatoes.

Here’s an important piece of information that my mother taught me years ago, but fewer and fewer people these days seem to know about. Green in potatoes indicates the presence of a rather harmful toxin. When you see patches of green in your potatoes as you peel them, cut out the green parts entirely and discard them.

What is the green? Actually it’s chlorophyll. Not bad for you at all. But the chlorophyll indicates that the potato has been exposed to sunlight. And where the potato has been exposed to light is where a natural toxin in the potato (solanine) becomes concentrated at harmful levels. So, never store your potatoes on the counter. Always keep them in a cool, completely dark place.

Solanine is a natural defense mechanism of the potato to ward off fungus and pests. It will also be triggered when a potato is bruised, so if your potato is at all damaged or bruised, discard it.

According to the Wikipedia, deep-frying potatoes at a high temperature (306°F) effectively lowers the level of toxins. But boiling them (212°F) has no effect. Best to stay on the safe side and just cut away the green parts. The NIH website mentions that the potato sprouts can also have concentrated solanine, so those too should never be eaten.

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One of the things we’ve been noticing recently is that more often than not the bag of potatoes we buy from our local grocer contains several potatoes with green splotches. Once in a while is one thing, but every time? We’ve complained to our store’s manager and if you are finding green in the potatoes from your produce supplier, we urge you to do the same.

Showing 4 of 58 Comments

  • Elise

    This potato thing is something I would probably never know about but for my mother. There’s nothing on the USDA website about it. The potato board websites don’t mention it. If you didn’t have someone take you by the hand and explicitly tell you about the potential problem with green potatoes, you might never learn about it.

  • Nick

    From what I’ve heard, potatoes always contain this toxin but to a much lesser extent. I wonder if the chemical builds up in your system like mercury can from eating too much tuna….I sure as heck don’t wanna turn green.

    All members of the nightshade family (tomatoes, eggplants, bell peppers, potatoes) have this toxin, but in low enough concentrations that it isn’t a problem. The toxins help repel pests. In the case of the potato tuber however, the solanine can become concentrated to harmful levels when exposed to light. Don’t know about build-up. Haven’t seen it mentioned as an issue. ~Elise

  • Anonymouse

    True story: I was talking to my grandmother about her childhood once, and she mentioned that she’d had a very young sister who died from eating a bad potato. I thought she was joking because she mentioned that it was green and that’s what made her sick, so it’s crazy to read this now.

  • Lalaine

    Thank you very, very much!
    We go through at least 100 lbs of potatoes at work (skilled nursing facility)on a weekly basis. This is a need-to-know info that I’ll be passing along to our cooks and to our suppliers as well.

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