Repeated tea use can leave visible marks inside a cup, especially on a light surface. The appearance of a mark does not by itself explain its cause, so start with the cup's material and care instructions.
Check the surface
Glazed ceramics, glass and metal have different care requirements. A mark in one cup should not be treated as proof that a tea has changed. Inspect the cup for damage as well as residue, and use the manufacturer's cleaning guidance.
Choose a compatible cleaning method
Avoid assuming an abrasive cleaner or household mixture suits every finish. Clean the cup using the method recommended for it, then rinse as directed. A damaged or rough surface may need a different response from an ordinary tea mark.
Keep comparisons practical
If you are comparing several teas, use clean cups so old aromas and residue do not confuse the tasting. A well-maintained cup makes the next brew easier to judge. Colour in a cup is not evidence of special strength or a medical property.
Explore K&M Herbs teas and gifts, or read our free Herbal Tea Wellness Guide.