How to check milk purity

Milk is an important part of our daily diet. From morning tea to children’s breakfast many families use it every day.

However milk that looks white and thick may not always be pure. It can sometimes contain added water, starch or other substances.

Some simple home checks can help you spot possible adulteration but they cannot provide final proof.  A certified food laboratory is the most reliable way to confirm whether milk is pure.

How to check for water

Milk mixed with too much water may look thinner than normal. Pour a small amount of milk onto a smooth clean surface and let it flow. If it runs very quickly and leaves little residue it may suggest that the milk has been diluted. However, this is only a basic check and cannot confirm adulteration.

How to check for detergent

Take a small amount of milk in a clean glass and add about the same amount of water. Shake or stir it gently.

If it produces unusually large amounts of foam that stay for a long time detergent may be present. Keep in mind that normal milk can also create some foam so this test alone is not conclusive.

How to check for starch

Starch may sometimes be added to make milk look thicker. For a basic check add a few drops of iodine to a small amount of milk. If the milk turns blue or dark blue it may indicate the presence of starch.

 A laboratory test is still needed for confirmation.

•What to look for when buying milk

Do not judge milk quality only by its color, thickness, or price. Pay attention if the milk looks unusually thin or thick or has a strange smell or taste.

When buying packaged milk check the seal manufacturing date and expiry date. After bringing it home, store it at the recommended temperature.

Note

Home tests can only give an early indication of possible adulteration. Laboratory testing is the most reliable way to confirm milk quality.