Milk Purity Test at Home: 3 FSSAI Checks You Can Try

A milk purity test at home is a quick way to spot obvious adulteration before you drink or cook with it. The Food Safety and Standards Authority of India, or FSSAI, has published simple methods in its DART booklet. DART stands for Detecting Adulterants with Rapid Testing.

Milk purity test at home: before you start

These checks use household items. They give a hint, not proof. A clean result does not mean the milk is perfect, and a doubtful result does not prove a crime. Still, they help you decide when to ask questions. So follow the FSSAI booklet for the exact procedure, because online descriptions can be unclear.

Test 1: water in milk

First, place a drop of milk on a smooth, tilted surface such as a polished plate. Pure milk runs slowly and leaves a white trail behind it. However, milk with added water runs fast and leaves no trail.

This is a basic test, but milk quality also varies by animal and season, so treat the result as a guide.

Test 2: detergent in milk

Mix 5 to 10 mL of milk with an equal amount of water in a clear bottle. Then shake it well. Thick, long lasting lather points to detergent. However, pure milk gives only a thin layer of foam.

Test 3: starch in milk

Boil 2 to 3 mL of the sample with 5 mL of water, and let it cool. Next, add 2 to 3 drops of iodine tincture. A blue colour shows that starch is present, so stop using that milk. For ghee or butter, skip the water.

Safety and good practice

Use clean glass or steel containers, and keep test samples away from food. Do not taste a sample that has chemicals in it. Then wash your hands after each test. Iodine tincture is a household antiseptic, but keep it away from children.

Know what the tests cannot do

Still, home tests catch only a few adulterants. However, they cannot detect every contaminant, and they cannot measure fat or protein. So for a firm answer, a licensed food lab is the right place. Buying from a trusted dairy and reading the pack label also helps. Our guide on how to read food labels in India explains what to look for on packaged milk.

What to do if milk fails a test

First, stop using that batch. Next, keep the pack or note the seller’s name and date of purchase. Then raise the matter with the seller or dairy. If you suspect unsafe food, our guide to Food Safety Connect shows how to report it. The tests above are drawn from FSSAI’s DART booklet, as summarised by Down To Earth.

Buying and storing milk safely

Packaged milk should carry the FSSAI licence number on its label, along with a use by or best before date. So check these before you buy. At home, boil loose or raw milk before drinking it, and keep packaged milk in the fridge. Also never leave opened milk out for long, because it spoils fast in warm weather.

FAQ

Which FSSAI test shows detergent in milk?

Mix equal parts milk and water, then shake. Dense, long lasting lather suggests detergent. Pure milk gives only a thin foam.

How do I test milk for starch?

Boil a small sample with water, cool it and add a few drops of iodine tincture. A blue colour indicates starch.

Are home milk tests reliable?

They are useful screening checks, but not lab proof. Use them as a guide, and report doubtful milk through official channels.