Green Potato (Aloo), Sprouts, New vs Old: How to Know if It’s Bad

Green skin on a potato is a warning light. The green itself is harmless chlorophyll, but it means the potato sat in light, and light also raises solanine, a natural bitter toxin that cooking doesn’t destroy. Cut a small green patch away deeply; bin the potato if it’s green all over, tastes bitter, or is soft and full of long sprouts. This guide covers how to know if a potato is bad, new vs old aloo, why some are yellow inside, and potato vs rice honestly.

Green potato: when to cut, when to throw away

Potatoes make glycoalkaloids (solanine is the famous one) to protect themselves from insects. They’re concentrated in the skin, eyes and sprouts, and they rise when potatoes see light, get bruised or get old.

Solanine doesn’t break down much with boiling or frying. So you can’t cook the problem away. You remove it.

1. Small green patch, potato firm: peel it, then cut out the green part plus about 5 mm of flesh around it. The rest is fine.
2. Green over a large area or deep into the flesh: throw it away.
3. Short sprouts (under about 1 cm), potato firm: dig out each sprout and its eye with the knife tip, peel, and cook.
4. Long sprouts, wrinkled and soft: throw it away.
5. Tastes bitter or makes your mouth burn: spit it out and bin the whole batch you cooked. That’s a sign of high solanine.
6. For children’s plates: use only fully clean, unsprouted, non-green potatoes. Their smaller bodies are affected by less.

Solanine poisoning is uncommon, but it happens. Signs include nausea, vomiting, stomach cramps, diarrhoea and headache, usually a few hours after eating. Mild cases pass, but seek medical help for repeated vomiting, confusion, a child with symptoms, or signs of dehydration.

How to know if a potato is bad

• Soft, mushy or leaking: bin it. Rot spreads fast to its neighbours, so check the rest of the bag too.
• Musty or rotten smell: often one hidden potato. Find it and remove it.
• Shrivelled and wrinkled but firm, no sprouts or green: it’s lost water. Fine to cook, better for mash than fries.
• Dark hollow in the middle when cut: hollow heart or black heart, from growing or storage stress. Cut out the damaged part; if it smells bad, bin it.
• Grey or pink after cutting: just air reacting with the flesh. Keep cut potatoes in cold water until you cook them.

Why is my potato yellow inside?

Usually because it’s a yellow-fleshed variety. That colour comes from natural carotenoid pigments and is completely normal. Many varieties sold in Pakistan and India are cream to yellow inside. Yellow only matters if it comes with softness, a bad smell or brown streaks.

New vs old potatoes, and which to buy for which dish

How to tell them apart at the stall: rub a new potato with your thumb and the skin flakes off. An old potato’s skin is set and slightly rough. New potatoes often have a little soil clinging and a fresh earthy smell.

How to choose potatoes in the market

1. Pick them one by one if the seller allows. Skip the pre-filled bag.
2. Look for any green tint, especially on the shoulders. Hold them up to the light if the stall is dim.
3. Squeeze each: rock firm. Any give at all, put it back.
4. Choose similar sizes (roughly fist size for curries) so they cook evenly.
5. Smell the pile. A musty whiff means rot hiding somewhere.
6. Buy 2 to 3 kg for a week for a family of four, unless you have a cool dark store.

Storing potatoes (and boiled potato in the fridge)

Raw potatoes want cool, dark and dry, with air around them: a basket or jute bag in the coolest room, away from the stove and never in sunlight. Keep them apart from onions, which prefer dry air while potatoes release moisture. Our summer aloo pyaz storage guide has the full method for hot months.

Can we keep potato in fridge? Raw ones, it’s not ideal. Cold turns some starch to sugar, so they taste sweet and brown too dark when fried. If summer heat leaves no choice, fridge them and use them for boiling or curry rather than fries.

Boiled potatoes: cool them within 2 hours, then refrigerate in a covered box and use within 3 to 4 days. One trap to know: never leave a baked potato wrapped in foil at room temperature for hours. The sealed warm space suits botulism bacteria. Unwrap it and fridge it once it has cooled.

Potato vs rice: the honest nutrition

A medium boiled potato with skin (about 170 g) has roughly 140 to 150 calories. Cup for cup, boiled potato has fewer calories than cooked white rice. It also gives far more potassium and a fair amount of vitamin C, which rice doesn’t have, plus some fibre, most of it in and near the skin.

Both are mostly starch and both raise blood sugar quickly. Frying is what changes the picture: a plate of fries or aloo pakoras soaks up oil and doubles or triples the calories.

A useful trick: boiled potatoes that are cooled (in aloo chaat or potato salad) develop some resistant starch, which digests more slowly. It helps a little. It doesn’t turn potato into a diabetes food. For people watching sugar, see our shakarkandi vs aloo comparison.

Two everyday recipes

Aloo chaat with a lighter hand (serves 2)

Boil 2 medium potatoes in their skins, cool fully, then cube. Add ½ cup boiled chana, 1 chopped tomato, ½ chopped onion, 1 tbsp imli chutney, a pinch of chaat masala and the juice of half a lemon. The chana brings protein and fibre that slow the meal down.

Aloo methi, dry (serves 3)

Heat 1 tbsp oil, add ½ tsp zeera. Add 2 cubed potatoes, a pinch of haldi, salt and chilli. Cover and cook on low 10 minutes. Add 2 cups chopped methi leaves and cook uncovered 5 more minutes. More methi tips in our fresh methi guide.

Good pairings: potato with dal, chana, eggs, dahi or leafy greens. Potato plus rice plus naan in one meal is simply a lot of starch; pick one.

Potato peel and potato on skin

Clean, non-green, unsprouted peel is edible and holds fibre. Scrub it under running water with a brush; no soap. Always peel away green skin and eyes.

A cold raw potato slice on tired eyes for 10 minutes is an old habit. It feels soothing because it’s cool and moist, a bit like a chilled spoon. Patch test on the inner arm first, keep it away from the eye itself, and don’t use it on broken or irritated skin. It won’t remove dark circles or lighten skin.

Potato myths

Myth: potatoes are fattening, so cut them out

A plain boiled potato is filling and moderate in calories. The oil, ghee and butter we add are what make potato dishes heavy.

Myth: boiling a green potato makes it safe

Solanine survives normal cooking. Cutting out the green or throwing the potato away is the only fix.

Myth: potatoes cause gas and joint pain

Some people find starchy meals bloating, which is personal. There’s no solid link between ordinary potato eating and joint pain.

Surprising potato facts

• Potato came from the Andes of South America and reached South Asia only a few centuries ago; there’s no potato in the oldest desi recipes.
• Shakarkandi isn’t a kind of potato. It’s a root from a different plant family.
• Okara district in Punjab is one of Pakistan’s best-known potato-growing areas.

More kitchen staples in Fruits and Vegetables.

Potato questions people ask