Coffee Powder — Water Screen for Clay or Heavy Mineral Matter

What FSSAI's coffee-clay check does

FSSAI DART gives a simple coffee-powder screen: add a small amount to water, stir, leave it for several minutes and inspect the bottom of the glass. Heavy clay-like material is expected to settle. The method is useful for flagging obvious earthy filler, but it is still a visual screening test.

Coffee fines can also settle

Ground coffee contains particles of different sizes, and some genuine fine particles may eventually sink. Kitchen Check should look for a distinct heavy mineral-like deposit rather than any brown material at the bottom. If the sediment is mixed and hard to distinguish, label the result unclear.

Use ground coffee, not instant coffee

This DART method is for roasted ground coffee powder. Instant coffee is manufactured to dissolve and behaves differently in water. Kitchen Check should disable this record when a user selects instant coffee. Product form matters to the validity of a rapid screen.

Do not infer chicory from sediment

Clay and chicory are different questions. Chicory has its own FSSAI water behaviour and legal labelling context. A bottom deposit in this record should not be labelled chicory. Kitchen Check should keep adulterants separate so one ambiguous observation does not become several accusations.

Use a clean glass and fresh water

Coffee residue from a previous cup can look like sediment. Rinse the glass well and use fresh water. If repeating, use a similar sample size and waiting time. Changing every condition makes the comparison meaningless.

Preserve evidence if the deposit is obvious

If repeated samples from one pack leave a substantial gritty or clay-like deposit, keep the pack, batch and purchase information. Do not add acid to identify the material. Official analysis is the safer next step.

Recommended result wording

Use 'No obvious clay-like heavy deposit', 'Some coffee fines settled—result unclear', or 'Distinct heavy earthy deposit seen—screen suspicious'. The result should not say 'coffee is pure' or name a mineral without confirmation.

Let the five-minute wait finish

Coffee particles move during the first moments after stirring. Reading the glass too early can confuse floating coffee with heavy sediment. The FSSAI rapid method includes a short waiting period, so Kitchen Check should use a visible timer and ask the user not to keep shaking the glass. A stable waiting period makes the observation easier to compare.

Do not compare instant and ground coffee

A user may try the same glass method with instant coffee and see very different behaviour because instant coffee is designed to dissolve. Kitchen Check should block that comparison. This record applies only to roasted and ground coffee powder. Product form must match the FSSAI rapid method before any interpretation is shown.