Infographic on the chemistry of tea. The graphic explains how polyphenol compounds are oxidised during tea processing, and these contribute to the flavour and colour of tea. Tea scum forms when hard water is used to make tea, a consequence of oxidised polyphenols adhering to calcium carbonate films on the surface. Tea's stimulant effect is due to caffeine, but it also contains L-theanine which has a calming effect.
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Ever wondered why tea’s stimulant effect feels different to that of coffee? Or why sometimes, when you make a brew, thin scum forms on the tea’s surface? On National Tea Day, here’s a graphic to answer those questions and more!

If you want to read more on tea chemistry, check out the previous graphic and article here, or the references below.

References and further reading