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Last Word is Â鶹´«Ã½â€™s long-running series in which readers give scientific answers to each other’s questions, ranging from the minutiae of everyday life to absurd astronomical hypotheticals. To answer a question or ask a new one, email lastword@newscientist.com
Why is tea more likely than coffee to leave a stain in the cup?
Chris Daniel
Glan Conwy, Conwy, UK
Tannins are complex, water-soluble organic compounds found in a wide range of plants, including tea and coffee. They are a type of polyphenol with antioxidant and anti-inflammatory properties, and are known for their bitter flavours and astringency.…
