Milk — Quick Screen for Detergent

What FSSAI's rapid screen looks for

FSSAI's consumer demonstration uses a simple observation: mix milk with an equal amount of water, shake it and look at the lather. Ordinary agitation can create some thin foam. A much denser, more persistent lather may raise suspicion that a detergent-like substance is present. Kitchen Check should make the word 'suspicion' prominent because foam behaviour is not the same as a laboratory chemical result.

How to perform the screen

Use a clean transparent container. Add a small amount of milk and the same amount of clean water. Close the container and shake briefly in a repeatable way. Set it down and observe the foam. The goal is not to shake for a long time until every sample becomes foamy. If the foam looks unusually dense and stable, mark the screen as suspicious rather than declaring adulteration.

Why normal milk can still foam

Milk contains proteins and fat, and shaking can naturally create bubbles. Container residue from dishwashing liquid can also produce misleading lather. That is why the container must be thoroughly rinsed and clean. Different milk types can foam differently. Kitchen Check should explain this before the test so users do not panic when they see any foam at all.

Do not taste suspicious milk

A sensory check is not needed here. If the screen gives unusually dense lather and the milk source is already doubtful, do not taste the sample to 'make sure'. The app should never ask users to ingest a food that they believe may contain a cleaning chemical. Set the sample aside and move to the official next step instead.

A home screen cannot identify the detergent

Even when the result looks suspicious, this method does not identify which surfactant or cleaning agent might be present, its amount, or whether another factor caused the foam. Formal testing uses controlled reagents and laboratory procedures. The rapid household version exists for awareness, not precise chemical identification.

What to record before reporting

Keep the package if there is one, note the brand or vendor, batch or lot number, date of purchase and where it was bought. A photo of the intact label can be useful. Do not contaminate the remaining product with household chemicals or repeated experiments if you may seek official testing. FSSAI provides routes for consumers to approach notified laboratories or Food Safety Departments.

Recommended result labels

Use 'thin foam only—no obvious detergent sign in this rapid screen', 'result unclear—repeat once in a thoroughly rinsed container', or 'dense lather observed—screen suspicious; do not rely on this alone'. Avoid green 'pure' badges and red 'dangerous chemical confirmed' badges. Those would claim more than the household screen can support.