Guide
Are Green or Sprouted Potatoes Safe to Eat?
The short answer
Green color and sprouts on potatoes signal elevated glycoalkaloids (solanine and chaconine), natural toxins concentrated in sprouts, eyes, and green skin that can cause headaches, vomiting, and digestive upset. Iowa State University Extension's food-safety guidance draws the line clearly: a still-firm potato with small sprouts is safe once the entire sprout and any green-tinged flesh are cut away, and skin-deep greening can be handled by peeling and cutting out all green portions, which removes most of the toxin.
Discard the potato when the sprouts are long (an inch or more) and the potato has shriveled, or when greening extends into the flesh beneath the skin. Do not count on cooking: baking, boiling, and frying do not destroy glycoalkaloids. A bitter taste or burning sensation in the mouth from cooked potatoes is the toxin announcing itself; stop eating. Prevent the problem by storing potatoes dark, cool, and dry, since light exposure is what triggers greening.
The keep-or-toss test
- Firm potato, few small sprouts: keep. Remove each sprout entirely, including the eye it grew from, and use soon.
- Firm potato, green only in the skin: keep. Peel and cut away every green area; the toxin concentrates in and just under green skin.
- Sprouts 1 inch or longer and the potato has gone soft or shriveled: toss.
- Green color extending into the flesh below the skin: toss.
- Cooked potato tastes bitter or causes a burning sensation: do not eat it.
Why cooking does not save a bad potato
Glycoalkaloids are heat-stable. Iowa State Extension states plainly that cooking does not destroy these compounds, so a deeply green or heavily sprouted, shriveled potato is not made safe by boiling or baking. Peeling before cooking does reduce the load, because the toxins concentrate in and near the skin, which is why fully trimmed, firm potatoes are considered fine to eat.
Why potatoes turn green
Light is the trigger. Exposure to light, on the kitchen counter, in a store bin, or in the garden when tubers grow too near the surface, causes the skin to produce chlorophyll (the visible green) and, alongside it, more glycoalkaloids. The green itself is harmless chlorophyll, but it is a reliable marker that toxin levels have risen in the same tissue. In the garden, hill soil over developing tubers so they are never exposed.
Storage that prevents the whole problem
Keep potatoes in the dark in a cool, well-ventilated spot, and buy or dig only what you can use before they sprout heavily. Warm kitchens accelerate sprouting; light causes greening. For curing temperatures and long-term storage setup, see our guide to storing potatoes over winter.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Iowa State University Extension AnswerLine - Sprouting or Greening Potatoes: Keep or Toss? — Firm potatoes with small sprouts are safe once the entire sprout and green-tinged parts are cut away; peel and cut out skin-deep green to remove most toxin; discard potatoes with sprouts 1 inch or longer plus shriveling, or green extending into the tuber; solanine and chaconine cause bitter taste, headaches, and vomiting, and cooking does not destroy glycoalkaloids.
- Michigan State University Extension - Is It Safe to Eat a Green Potato? — Green skin on potatoes indicates chlorophyll from light exposure and accompanying solanine formation; green and sprouted portions should be removed before eating.
- National Capital Poison Center - Are Sprouted Potatoes Safe to Eat? — Solanine and chaconine in green or sprouted potatoes can cause illness; the highest concentrations are in leaves, eyes, green skin, and sprouts, and the bitter flavor usually limits how much people eat.