Why Do Your Potatoes Look Green? (Explained)

Potatoes turn green due to chlorophyll, which forms when exposed to light, indicating the presence of solanine, a harmful toxin. Consuming green potatoes, especially if bitter, can cause illness. To avoid this, store potatoes in a dark, cool place and remove any green spots before cooking.

Have you brought potatoes home from the grocery store and looked at them and wondered “Why do my potatoes look green?” You didn’t notice this in the store.

Now what? In this article, I am going to explain why this happens.

And what you can do.   

why do my potatoes look green?
From Our Garden

Why Do My Potatoes Look Green?

When exposed to light for an extended amount of time your potatoes will turn green. This is Chlorophyll which in itself is not a bad thing. 

But it does indicate the presence of solanine which is a toxin and if too much is consumed can cause vomiting and diarrhea. When planting potatoes, you need to “hill” them, meaning piling the soil on and around the plants when they emerge from the ground. 

Why? Because as they grow, the potatoes will push up through the soil and are exposed to sunlight and then will turn green.

Potatoes like the dark and if stored properly you can avoid them from turning green. But there are times when you bring home some potatoes from the grocery store that have already turned a little green.

What to do then? Do you need to throw them out? 

Read on and I will explain your options.

Can You Eat Green Potatoes?

If the whole potato is green, I would just throw it out. Especially if the taste is bitter. 

The bitter taste indicates the presence of solanine which is a toxin. Consuming solanine can cause gastrointestinal upset such as vomiting and diarrhea. 

If too much solanine is consumed it can be deadly. Years ago when I was first married, I didn’t know any better and I cooked some green potatoes. 

My husband became sick with an upset stomach. Needless to say, now I am very careful when it comes to green potatoes!

Not only am I careful but my husband will remind me to check the potatoes before using them. Of course, we grow our own potatoes so when my husband digs them up, he throws the green ones away. 

When we run out, I have to buy them at the grocery store. (We eat a lot of potatoes).

My husband also loves mashed potato salad.

How To Fix a Green Potato

If there are only a few green spots that are mainly on the surface such as the skin, you can peel or cut out these areas. If the green is extensive such as penetrating deep into the potato, the best thing to do is just throw it out.

Always better to be safe than sorry. 

Fried potatoes

Solanine can be destroyed by frying, however, boiling will not get the job done. So if several of your potatoes are green it would be better to fry up some fried potatoes instead of making the mashed potatoes that you had originally planned. 

Who doesn’t love fried potatoes with some onion? Not me!

But honestly, I still try to cut out as much of the green as I can, especially if there are several that are green. To this day, as expensive as groceries are, I try to salvage as many as I can.

The Proper Way to Store Potatoes

The best way to store potatoes is in a dark cool place. Direct sunlight is going to make those potatoes turn green. 

Many use a container with a lid on it made especially for storing potatoes. My kitchen has limited space so I keep mine in a washpan in my pantry. 

I have to keep mine up off the floor or my dog will attempt to eat them. I don’t always close my pantry door and one day I found several potatoes scattered across my kitchen floor with bites taken out of them. 

Honestly, sometimes I think pets are worse than kids! She is a poodle that weighs a whole 10 pounds. 

My Final Thoughts

  • Potatoes turn green due to exposure to light, which increases chlorophyll production, similar to how apples can become sunburned and develop a greenish color on their skin when exposed to too much sunlight.
  • The green color in potatoes is often associated with the presence of solanine, a natural toxin, akin to the bitterness in green almonds or unripe tomatoes, which also contain natural toxins.
  • Consuming large amounts of green potatoes can lead to solanine poisoning, with symptoms like nausea and headache, similar to the effects of eating too many unripe persimmons, which can cause digestive discomfort.
  • To prevent potatoes from turning green, they should be stored in a dark, cool place, just as onions and garlic are stored away from light to prevent sprouting and bitterness.
  • It’s advised to cut away the green parts of a potato before cooking, much like removing the sprouted parts of garlic or the eyes of a potato, to reduce the risk of consuming solanine.

Extensive sunlight causes potatoes to turn green by producing chlorophyll. Which in itself is not a bad thing. 

But the presence of chlorophyll also indicates solanine which is not so good. It is considered a toxin and if consumed can cause gastrointestinal problems. 

If too much is consumed it can be deadly. To avoid consuming the solanine, you can just peel or cut out the green areas, but sometimes the green has penetrated deep into the potato. 

If that has happened then it is best to just throw it out. Solanine cannot be destroyed by boiling, however, it can with frying.  

Storing your potatoes in a dark cool place is the best practice to avoid green potatoes. But that is not always feasible as you are likely on occasion to bring them home from the grocery store with some with green areas. 

I hope this article was helpful in “Why do my potatoes look green?” Please leave me a comment below with your thoughts.

And as always, have a wonderful day!

FAQ: Why Do My Potatoes Look Green?

1. Why do potatoes sometimes turn green?

  • Potatoes turn green when exposed to light. This exposure increases chlorophyll production, which is a natural process also seen in other plants. While chlorophyll itself is harmless, its presence often coincides with higher levels of solanine, a natural toxin that can be harmful if ingested in large quantities.
  • To avoid this, it is recommended to store potatoes in a dark, cool place and remove any green areas before cooking.

2. Is it safe to eat green potatoes?

  • Consuming small amounts of green potato is generally not harmful for most people, but it’s best to avoid eating large amounts of the green parts due to the potential solanine content.
  • If potatoes are very green or taste bitter, it’s safer to discard them to avoid the risk of solanine poisoning, which can cause nausea, headaches, and other digestive symptoms.

3. How can I prevent my potatoes from turning green?

  • Storing potatoes in a dark, cool, and dry place can significantly reduce their exposure to light, thus preventing them from turning green.
  • Avoid storing potatoes near onions, as gases from the onions can hasten spoilage and contribute to the greening process.

4. What should I do with potatoes that have turned green?

  • If the greening is very light, you can often just peel the green parts off and use the rest of the potato. Cooking does not reduce the solanine content, so it’s important to remove the affected areas.
  • For potatoes that are extensively green or have a bitter taste, it’s best to discard them entirely to avoid the risk of toxicity.

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