How to check ghee purity at home

You can screen ghee at home with a few kitchen tests: melt a little on your palm, heat a spoonful in a pan, chill the jar, add iodine to half a teaspoon to check for starch, and read the label. Each test rules out one kind of adulteration. None is a laboratory result; passing all of them is screening, not proof.

A kitchen test is an indication, not a lab result. It can tell you that something is wrong; it cannot tell you that everything is right.

What adulterated ghee usually contains

Ghee is expensive because it takes 25 to 30 litres of milk to make a litre, so the incentive to stretch it is strong. The usual additions are vanaspati and other hydrogenated vegetable fats, cheaper oils such as palm oil, animal body fat, starch (mashed potato, sweet potato or flour) for bulk, and colour to make a pale blend look like cow ghee. Each of the tests below is aimed at one of these. What adulterated ghee looks, smells and tastes like describes the signs in more detail.

The tests

1. The palm test: does it melt at body heat? Put a quarter teaspoon of ghee on your palm and wait. Pure cow ghee softens within seconds and melts to a clear oil, because butterfat melts at roughly 32 to 35 degrees Celsius, below skin temperature. Ghee that stays waxy or leaves a hard white film may contain vanaspati or other hydrogenated fat. What it cannot show: liquid vegetable oils melt too, so oil mixed into ghee passes this test.
2. The pan test: how does it behave when heated? Heat a teaspoon of ghee in a small pan on a low flame. Pure ghee melts at once, turns clear and golden, foams a little and then browns slowly with a nutty, roasted smell. Ghee that foams heavily, spits, darkens quickly or smells flat and oily may be mixed with other fats or carry extra moisture. What it cannot show: this is a judgement of smell and colour, and it varies with the cow's feed and the season.
3. The cold test: does it set as one fat or two? Put the jar in the refrigerator for a few hours. Pure ghee sets evenly into a single colour and grain. If it separates into distinct layers, one harder or whiter than the other, two fats with different melting points are probably present. What it cannot show: natural grain and a paler top layer can occur in pure ghee too, so read layers as a prompt to test further, not as proof.
4. The iodine test for starch (FSSAI DART) Take half a teaspoon of ghee in a transparent glass bowl and add two or three drops of tincture of iodine. If a blue colour forms, starch is present: mashed potato, sweet potato or flour added for bulk. This test is published by FSSAI in its DART (Detect Adulteration with Rapid Test) booklet. What it cannot show: anything about fats. It detects starch only.
5. Read the label The label must carry an FSSAI licence number; look it up on the FSSAI site. The ingredient line should say cow milk fat, cow ghee or similar and nothing else; ghee is a single-ingredient food. Words such as pure, shuddh, bilona, Vedic and hand-churned are claims with no legal definition. Agmark grading is a real mark but voluntary. What it cannot show: a correct label can sit on an adulterated jar; it only tells you who to hold responsible.
6. Do the arithmetic on the price It takes 25 to 30 litres of cow milk to make one litre of ghee. Multiply the local price of cow milk by 25 and you have the cost of the milk alone, before any labour, fuel, packaging or delivery. A litre of cow ghee offered for less than that cannot have been made from that much cow milk. What it cannot show: a high price is not proof of purity either.

The palm test is covered on its own in The palm test for ghee: what it shows and what it does not, and all five kitchen checks in Five ways to check if your ghee is pure at home. The label is taken line by line in Reading a ghee label and What FSSAI rules say about ghee labelling; the price arithmetic in What a fair price for bilona ghee looks like.

Two things that are not purity tests

• Grain. A grainy (danedar) texture forms when ghee cools slowly. It is normal in traditionally made ghee and reassuring to see, but adulterated ghee can be grainy and pure ghee can be smooth. Does grainy ghee mean it is pure?
• Colour. Cow ghee is yellow because cows pass carotene from green feed into their milk fat; buffalo ghee is white because buffaloes convert it to colourless vitamin A. Colour says which animal, and something about its feed, not whether the jar is pure. Why some ghee is yellow and some is white.

What a laboratory does that a kitchen cannot

A food-testing laboratory analyses the fat itself. The standard checks for ghee in India include the Reichert-Meissl value (a measure of the short-chain fatty acids that are characteristic of milk fat and scarce in vegetable fats), the butyro-refractometer reading (how the fat bends light, which shifts when foreign fat is present), the Baudouin test (a red colour that detects sesame oil, which Indian rules require vanaspati to contain precisely so that it can be found in ghee), moisture and free fatty acid content, and increasingly a fatty-acid profile by gas chromatography and a check for plant sterols, which do not occur in pure milk fat. FSSAI-notified and NABL-accredited laboratories run these tests for a fee. If a jar matters, that is the test that settles it. There is one home test that uses laboratory chemistry, mixing melted ghee with concentrated hydrochloric acid and sugar to look for a red colour; it needs a corrosive acid and is better left to a lab.

Before you buy rather than after

The cheapest purity test is to buy from someone who will show you how the ghee is made. Questions to ask a ghee seller before you buy and Buying ghee online in India: what to check before you pay list what to ask. Organic Farmz makes A2 Gir cow ghee by the bilona method in Delhi, makes each jar after the order is placed, sends buyers photographs and videos of their own batch on WhatsApp, and links its lab reports from the top of every page. The ghee is sold by the litre: Rs 1,400 a litre for 1 to 2 litres, Rs 1,300 a litre for 3 to 4 litres and Rs 1,200 a litre for 5 litres or more.

Sources

• Food Safety and Standards Authority of India, DART: Detect Adulteration with Rapid Test, the household testing booklet (milk and milk products, test for starch in ghee and butter).
• Bureau of Indian Standards, IS 1746 (sesame oil), on the addition of sesame oil to vanaspati as a marker for detecting adulteration of ghee.