Fake or Polished Daal: Metanil Yellow, Khesari and Home Checks

The real danger in “fake daal” isn’t plastic or polish. It’s two things: a banned yellow dye called metanil yellow, sometimes used to brighten arhar and chana daal, and khesari (grass pea), a cheap look-alike that caused paralysis when poor families had to live on it. A glass of warm water can flag heavy dye, but no home test can prove a daal is safe. What protects you is where you buy, what you look for in the grain, and knowing how to report a bad batch.

The real hazards: dye and khesari, not “plastic daal”

Plastic daal isn’t a thing; moulding plastic into split-pea shapes would cost more than the daal. Polish, while often oversold as a poison, is mostly about looks. The two problems food inspectors actually find in daal markets are different, and one of them is serious.

Metanil yellow and other dyes

Metanil yellow is an industrial azo dye made for textiles and paper. It isn’t allowed in food in Pakistan, India or most other countries, yet it still turns up now and then in arhar daal, chana daal, matar daal, besan and haldi, because a little of it makes dull, old or cheaper stock look bright and fresh, and since animal testing links regular intake to harm in the nerves and liver, the only sensible amount in your food is none at all.

Khesari (grass pea)

Khesari is a hardy pulse that grows through drought, which is why it became the food of last resort during famines in India, Bangladesh and Ethiopia. It contains a natural nerve toxin (called ODAP). When people ate khesari as their main food for two or three months or more, some developed lathyrism: a sudden, permanent stiffness and weakness of the legs. There’s no reversing it. India banned its sale in 1961 in most states; some states have since relaxed that, and plant breeders have produced low-toxin varieties. An occasional small amount mixed into your daal is not known to cause lathyrism, which needs heavy, long-term eating, but you should still get what you paid for, and khesari mixed in and sold as arhar or chana daal is plain fraud.

What “polished” and “unpolished” daal really mean

Almost all daal is polished a little. After splitting and skinning, the grains go through machines that rub off dust and husk, sometimes with a spray of water and a touch of edible oil, and sometimes over leather-lined rollers that buff them to a shine. That’s where the rumour “daal is polished with leather” comes from. The leather is on the machine, not in the daal.

Arhar is the one most often oiled, and “oily toor”, coated in edible oil (traditionally castor oil in some regions) to keep insects off in storage, is a normal, permitted Indian product as long as the oil is food grade and the pack says so; the worry only starts when non-food oil or colour is used to make old stock look new. Big difference.

“Unpolished” on a pack has no strict legal definition in most places. It usually means no oil, no colour and minimal buffing, which is good, but it’s a marketing word rather than a test result, it doesn’t guarantee more nutrition, and you’ll usually pay more for it. Honest unpolished daal looks slightly dull and uneven. Never sticky.

How to spot dyed daal at home, and what the test can’t tell you

Do this with a spoonful from every new bag of yellow daal. It takes two minutes.

1. Look in daylight. Spread a tablespoon on white paper. Natural arhar and chana daal have a warm, slightly uneven yellow. Be suspicious of a flat, lemony, almost glowing yellow where every grain is identical.
2. Rub test. Rub a few grains firmly between damp fingers or on a wet white tissue for 30 seconds. A strong yellow smear that comes off easily is a warning.
3. Warm-water test. Put 1 tablespoon daal in a clear glass with 1/2 cup warm water. Stir and wait 5 minutes. Natural daal leaves the water clear or very faintly cloudy. Bright yellow water, or a yellow ring on the glass, suggests added colour.
4. Check the rinse. When you wash daal for cooking, the first rinse should look cloudy and starchy, not yellow like haldi water.
5. Smell it. Good daal smells of nothing much, or faintly nutty. A chemical, paint-like or kerosene smell means don’t cook it.

Be honest about the limits. A clear glass of water doesn’t mean the daal is clean: small amounts of dye, pesticide residue, mould toxins and khesari all pass straight through a water test. Labs confirm metanil yellow with an acid reagent; please don’t try chemical tests at home, and never taste a daal you already suspect. The water test is a filter for obvious fraud, nothing more. The same approach works for fresh produce in our guide to dyed vegetables, peas and chillies.

How to spot khesari mixed into arhar or chana daal

Khesari doesn’t look like a half-sphere. That’s the giveaway.

• Shape: khesari splits are angular, almost square or wedge-shaped, with a sloping edge, a bit like a small tooth. Arhar and chana daal are rounded.
• Colour: khesari is duller, greyish-white to muddy yellow, and it’s sometimes dyed to match arhar, which is where the two frauds meet.
• Size: usually a little smaller and flatter than chana daal.

Spread the daal on a thaal and look. If you can pick out a handful of angular grains that clearly don’t belong, return the bag or stop buying from that seller. And remember the chana-matar swap too: smooth, round, paler half-spheres in your “chana daal” are matar daal, cheaper but harmless. Our chana daal guide shows what the real grain should look like.

Grit, stones and insects

This is the one “adulteration” every household meets. Stones and mud lumps the size of a grain slip past mill sieves. Weight is money.

The fix is old and it works: pick the daal on a thaal in good light before washing, pushing it across the plate a small heap at a time, then wash it in a deep bowl, swirling with your hand, and tip the water and daal off slowly into a second bowl, because stones are heavier than daal and stay behind at the bottom. Weevils, holes and webbing are a storage problem, not a fraud one, and our weevil-proof atta and daal storage guide covers every method that actually works. Daal that smells musty or has visible green, grey or black mould goes in the bin, not the pot, because mould toxins survive cooking.

Myth: Masoor daal is banned

It isn’t. Masoor is sold everywhere in Pakistan and India, and both countries import large amounts of it, much of it from Canada and Australia. The rumour tangles together a few real things. Regulators do test imported pulses for pesticide residue, individual shipments are occasionally rejected, and some Hindu families traditionally avoid masoor for religious reasons. No ban.

A second myth says khesari is so poisonous that one plate will paralyse you. Also wrong, and it’s worth knowing why: lathyrism came from months of eating khesari as the main food during famine. That’s the reason to avoid buying mixed daal, not a reason to panic over a meal you’ve already eaten.

Buying safer daal, and how to report a bad batch

You can’t lab-test your shopping. You can stack the odds.

• Buy sealed packs from known brands with a batch number, packing date and a food authority licence or registration number printed on them. That makes a complaint traceable.
• Loose daal is fine from a busy, trusted shop with fast turnover. Avoid unusually cheap “chana daal” or “arhar” that’s much below the going rate.
• Keep the pack or a sample if something seems off. It’s your evidence.

To report in Pakistan, contact your provincial food authority: the Punjab Food Authority, Sindh Food Authority, Khyber Pakhtunkhwa Food Safety and Halal Food Authority, or Balochistan Food Authority, all of which take complaints through their helplines, websites or apps. In India, use FSSAI’s Food Safety Connect app or website, or your state’s food safety commissioner. Give the shop name, date, brand, batch number and a photo. For more on the whole family of pulses, browse our Grains, Daals & Pulses section.

Fake and polished daal: your questions