Do you want to know how to tell if potatoes are bad? Can you eat potatoes when they are already sprouting? Can I store potatoes in the fridge or are they no longer edible?
We explain some of the warning signs. If you spot them on potatoes, you’d better discard them.
How To Tell If Potatoes Are Bad?
Even if it is often assumed that the potato is no longer edible when the first sprouts sprout, this is possible without hesitation. The germs can be removed together with the skin, and the potatoes are then processed as usual.
Potatoes should only be discarded when the sprouts are about five centimeters long, as too much of the toxic solanine may have formed inside the tuber. Potatoes also often get green spots over time, which also contain the toxic substance solanine. But if these are cut out generously, the potato can still be eaten.
When to stop eating potatoes?
Potatoes are almost 80 percent water. The rest of the potato shines with vitamins (e.g. vitamin C, B1, B2, B6) and minerals (magnesium, potassium, calcium, phosphorus, and iron). Reason enough to eat them – but wait!
Because there are a few circumstances where we should rather stay away from them after knowing the answer to “How to tell if potatoes are bad? “. We show you seven pointers to watch out for bad potatoes.
1. If they have been stored in the refrigerator
The UK Food Standards Agency warns against storing potatoes in the fridge. Because in the refrigerator, the starch contained in potatoes turns into sugar. If the potatoes are baked or fried, this sugar combines with the amino acid acrylamide. This increases the risk of developing cancer, as tests with rodents have shown. So ideally we should store potatoes in a dark, dry, cool (preferably 4-6 degrees) place instead of in the fridge.
Tip: It is best to store the potatoes in linen, jute, or mesh bags! In foil bags, on the other hand, they rot very quickly.
2. If they have long sprouts or green spots
Sprouted potatoes do not taste good and have already lost many of their nutrients. If the germs are green, it is a sign of a high level of solanine – a toxic chemical compound that can lead to nausea, drowsiness, kidney inflammation, and cardiac arrhythmia (lethal dose: 400 mg). At temperatures between seven and ten degrees Celsius, the quality of the potatoes is maintained – there is no germination. Potatoes only begin to sprout from around 12 to 14 degrees.
Tip: If the sprout is only about one centimeter long, the solanine content of the tuber changes only slightly (last chance to eat the potatoes! But first cut off the parts because they taste bitter). If the germs are more than 10 centimeters long, they are no longer suitable for consumption. The same goes for green tubers that have been exposed to too much light.
3. When they are unpeeled
The Federal Institute for Potato Research recommends not eating potato skins. The reason: with longer storage, the solanine content (see above) in the shell is increased. And: Potatoes are often sprayed with pesticides to keep pests away.
Tip: If you don’t want to do without the potato peel, you should make sure that the potatoes come from organic farmers and are freshly harvested. Washed very thoroughly before preparation, you can also enjoy them with their skins on.
4. If they smell unappetizing
Spoiled potatoes smell sweet and musty. Good tubers, on the other hand, can be recognized by their pleasant, earthy smell.
5. If they have wet spots
If the potatoes are wet in places, it is a sign that they are infested with fungi and bacteria (e.g. Erwinia caratovora) – and thus a case for the garbage can!
Tip: When storing, make sure that potatoes do not come into contact with salt, as this attracts water vapor. The moisture can migrate to the potato and encourage wet rot.
6. If they don’t have ‘(inner) beauty
If the tubers are spotted, they are covered with scabs. The brown, cork-like spots are cracked and coat the potato. black spotting (caused by pressure; the potato turns gray at the affected area, then turns blue and then black) and “internal” defects (e.g. hollowness – brown-rimmed cavities inside the tuber -, iron spotting – rust-brown spots caused by virus infection and growth disturbance -, Glassiness – the inside of the potato is very light and has a watery, glassy consistency, caused by disturbances in the starch balance) are only visible when they are cut.
7. When there are raw onions in the potato salad
Onions are never sterile. Because of this, they can contain lactobacilli, yeast, or mold, which can multiply well on the damp surface of a finely chopped onion – especially if the lettuce is kept at temperatures above 7 degrees.
The above are the symptoms shown by bad potatoes and by knowing them you can also answer the question, “how to tell if potatoes are bad?”
Tip: If you don’t want to do without raw onions in potato salad, you should only mix them in and add lemon juice or vinegar immediately before eating! This ensures an acidic pH value that inhibits germ growth.
How long do potatoes keep?
The shelf life of potatoes, unlike other vegetables, is quite long. If stored properly, they can be kept for several months.
- Only new potatoes should not be stored for longer than two weeks.
- Frozen potatoes have a shelf life of about 12 months.
- Frozen potato dishes have a shelf life of about three months.
Can you freeze potatoes?
Potatoes can only be frozen to a limited extent. Potatoes should not be frozen raw as this will convert the starch into sugar. Boiled potatoes, on the other hand, are good for freezing. This can be done whole, in larger pieces, or in slices.
Freezing Tip: The potato should not be overcooked and should be completely cool before freezing.