Why is it looks like my potatoes are sprouting and are they safe to eat?

December 16, 2025 •

4 min read

Potatoes are part of the nightshade family and produce natural toxins called glycoalkaloids that can increase with age and exposure to light. So, why is it looks like my potatoes are sprouting and are they safe to eat? The answer depends entirely on their condition.

Quick Summary

Potatoes sprout naturally due to age and storage conditions like warmth and light exposure. Safety hinges on the potato's firmness and presence of green skin; remove sprouts and green parts, but discard if soft or extensively damaged.

Key Points

Sprouts Contain Toxins: The sprouts and green parts of a potato have high concentrations of glycoalkaloid toxins, like solanine.
Toss If Soft or Green: Discard any potato that is soft, shriveled, or extensively green, as this indicates a dangerous level of toxins throughout.
Trim Small Sprouts: If the potato is firm and has only small sprouts, it's safe to eat after thoroughly cutting out the sprouts and any green areas.
Proper Storage is Key: Store potatoes in a cool, dark, and dry location, away from onions, to prevent sprouting and extend their shelf life.
Cooking is Not Enough: High heat from cooking does not effectively destroy the glycoalkaloid toxins, so physical removal of affected areas is essential.
Bitter Taste is a Warning Sign: A potato with a bitter flavor, even after cooking, suggests high levels of toxins and should not be consumed.

The Science Behind Potato Sprouting

Potatoes are living tubers, and sprouting is a natural part of their life cycle. The 'eyes' on a potato are actually buds. When conditions are right, the potato is stimulated to break its dormancy and begin growing a new plant. The primary drivers of this process are environmental factors and the potato's age.

Why Warmth, Light, and Time Matter

Warmth: Storing potatoes in warm conditions, especially above 45°F (7°C), can signal the potato to end its dormant period and begin sprouting prematurely. The average kitchen temperature is often ideal for this process.
Light Exposure: Exposure to light, even indirect, triggers two significant changes in a potato: the production of chlorophyll, which causes it to turn green, and the production of glycoalkaloid toxins, particularly solanine.
Storage Time: Like all produce, potatoes have a shelf life. As they age, they naturally use their stored starches to fuel the growth of sprouts.

Glycoalkaloids: The Key Toxin in Sprouted Potatoes

The main safety concern with sprouted potatoes is the presence of glycoalkaloids, primarily solanine and chaconine. These are natural toxins that the potato produces as a defense mechanism against insects and diseases. While present in low levels in fresh potatoes, their concentration significantly increases in the sprouts, green skin, and bruised areas.

The Dangers of Glycoalkaloids

Consuming high levels of glycoalkaloids can cause gastrointestinal and neurological problems. While severe poisoning is rare, mild symptoms are more common. Possible side effects include:

Nausea and vomiting
Stomach cramps and diarrhea
Headaches and fever
A burning sensation in the mouth

It is crucial to note that cooking does not eliminate solanine effectively, as the compound is heat-resistant.

Is It Safe to Eat a Sprouted Potato? The Green and Firmness Test

Your decision to eat or discard a sprouted potato depends on its overall condition. Use your senses to determine its safety.

Safe vs. Unsafe Sprouted Potatoes


Condition	What to Do	Reason
Firm with small sprouts	Safe to eat after removing sprouts and any green parts.	The toxin concentration is likely still low, primarily confined to the sprouts.
Firm with extensive greening	Unsafe, should be discarded.	Greening indicates higher solanine levels throughout the tuber, even if firm.
Soft, shriveled, or wrinkled	Unsafe, should be discarded.	These are signs of spoilage and potential high toxin levels throughout.
Extremely long sprouts	Unsafe, should be discarded.	Very long sprouts suggest significant aging and high toxin buildup.

How to Prepare Salvageable Spuds

If your potato is firm and only has small sprouts, follow these steps to prepare it safely:

Cut the sprouts off: Use a sharp paring knife or a vegetable peeler's tip to dig out and remove the sprouts completely.
Peel thoroughly: Remove all the skin, particularly in areas with a green tinge, as solanine is concentrated just beneath the surface.
Inspect again: Look for any green flesh and cut it away. If the greening is widespread or deeply set, it is best to throw the potato away.
Taste for bitterness: If the potato has a bitter taste after cooking, it is a sign of high solanine content and should not be eaten.

Proper Storage to Prevent Sprouting

Preventing sprouting is the most reliable way to ensure potato safety and longevity. Proper storage is key.

A Quick Guide to Optimal Storage

Do store in a cool, dark, and dry place: A pantry, basement, or root cellar is ideal, where temperatures are between 40-45°F (4-7°C). Store them in a breathable basket or paper bag to ensure good airflow.
Do not refrigerate raw potatoes: The cold temperature converts the potato's starch to sugar, affecting flavor and texture.
Do not wash until ready to use: Washing adds moisture, which can encourage both sprouting and rotting.
Do not store with onions: Onions release ethylene gas, which can accelerate the sprouting process in potatoes. Some evidence also suggests that storing potatoes with apples may help inhibit sprouting due to ethylene, but this is debated.
Do use them soon after purchasing: Sprouting is a sign of age, so buy only what you need to use within a few weeks.

Conclusion: When in Doubt, Throw It Out

When you see your potatoes are sprouting, it's a natural process driven by time and storage conditions. The danger lies in the buildup of glycoalkaloids, toxins like solanine, concentrated in the sprouts and green areas. If a potato is still firm with small sprouts, you can safely prepare it by removing the eyes and green skin. However, if the potato is soft, shriveled, or has extensive green discoloration, it is best to discard it entirely to avoid the risk of food poisoning. To minimize waste, always store your potatoes in a cool, dark, and dry place and use them promptly.

For further details on food safety standards, you can refer to the official information provided by the USDA.

Frequently Asked Questions

Solanine is a type of glycoalkaloid, a natural toxin found in plants of the nightshade family, including potatoes. Its concentration increases in the sprouts and green parts of the potato, potentially causing illness if consumed in large quantities.

Yes, peeling and cutting out the sprouts and any green areas is the best way to remove the toxins. Solanine is most concentrated in the skin and sprouts, so thorough peeling is crucial for a potato that is still otherwise firm.

No, it is not recommended. The green color indicates the presence of solanine, which is heat-resistant. Cooking will not eliminate the toxin, and the potato should be discarded, especially if the greening is widespread.

Consuming a toxic sprouted or green potato can cause mild to severe symptoms, including nausea, vomiting, stomach cramps, diarrhea, and headaches. If you experience severe symptoms, seek medical help.

Potatoes sprout faster when stored in warm, humid, or brightly lit conditions. These environmental factors mimic the conditions for growth and trigger the sprouting process. Storing them with onions can also accelerate sprouting.

Store potatoes in a cool, dark, and dry place, such as a basement or pantry, away from direct sunlight and onions. A paper bag or basket is ideal for ventilation.

If the potato is soft, shriveled, or has extensive green patches or very long sprouts, it is too far gone and should be thrown out. These signs indicate high toxin levels and overall degradation.