<
https://theconversation.com/from-river-stain-to-your-cup-of-tea-the-secret-world-of-tannins-271730>
"While stopped in heavy Melbourne traffic recently, I noticed that what looked
like a shadow under a row of spotted gums (
Corymbia maculata) along a major
road was actually a stain on the concrete kerb.
As a botanist, it caught my attention; biological stains always have an
interesting story attached.
Stains like these – under many tree species, on your car after certain leaves
have fallen on them, and on your timber deck after rain has washed leaves onto
it – are from tannins leaching out of foliage.
Tannins are astringent and bitter-tasting chemicals found in many leaves;
they’re what add flavour to red wines, chocolate and tea. Oak timber is high in
tannins, and it’s the tannins in oak barrels that enrich the flavour of some
wines.
So tannin stains on concrete, cars and decks may be unsightly, but that doesn’t
mean tannins are unimportant."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
