Could your milk contain detergent? FSSAI shows easy test to check at home

Milk is a daily staple in many Indian homes, but concerns over adulteration often raise questions about its quality. Detergents are among the substances discussed in connection with milk adulteration, as they can be used to give diluted milk a thicker or frothier appearance.

The Food Safety and Standards Authority of India (FSSAI) has demonstrated a simple test that can be done at home to check for possible detergent adulteration.

How to test milk for detergent

In a video shared on Instagram, FSSAI showed a quick method that requires only a small quantity of milk and a glass.

To carry out the test, take around 5-10 ml of milk in a small glass and shake it vigorously. The next step is to observe whether bubbles form and how they behave.

According to the test demonstrated by FSSAI, milk that does not produce bubbles after being shaken is considered unadulterated. Visible bubble formation, meanwhile, indicates possible adulteration with detergent.

Why does detergent cause bubbles?

The difference comes down to surface tension. Pure milk has relatively high surface tension, so any air pockets created while shaking tend to disappear quickly.

Detergents contain surface-active substances, also known as surfactants. These reduce the liquid's surface tension and help stabilise air bubbles. As a result, bubbles can remain visible for longer when detergent is present.

The test is therefore based on the different reactions of the liquid when it is shaken.

Tips to avoid adulterated milk

Consumers can also take a few precautions when buying milk. Choosing products from reputable brands that comply with food safety regulations is one step.

Before buying packaged milk, check the seal, packaging and ingredients, along with the relevant safety information. Consumers can also look for the FSSAI logo and verify the 14-digit licence number displayed with it.

The way milk pours can also offer a basic physical check of its consistency.

The source material also recommends choosing Tetra Pak cartons over plastic pouches, noting that pouches have a shorter shelf life and can be vulnerable to tampering or temperature-related problems during distribution.