Alexis,
Tannins are a subclass of phytochemicals under the class of polyphenols. Polyphenols and tannins are found in almost all plants.
Depending on chemical definition of the subclass, tannins exist in tea. Examples are gallic acids and various flavones. Some scientists define certain catechins as tannins and some do not agree.
To me, the terminology does not really matter.
It is scary to think that one would be drinking something that contains the chemicals that would tan the leather of one’s shoes, but it really is a matter of clarification of concepts. Same as you would not wear a charcoal ring for the wedding or burn diamonds for your barbecue; both are carbon.
Generally tannins are astringent in taste. They are a major reason for the astringency in almost all fruits, particularly the skins, as well as veggies and, tea. Tannin is present in almost all plant products that we consume, in various amounts.
In order to avoid confusion, we always group the tannins in tea with the other major polyphenols, such as flavonoids and catechins, and understand them as polyphenols, which they are.
If the tannic acid you talk about refers to the chemical that they use to tan leather, it is extracted from the tree barks of certain species (depending on the manufacturer) and mixed in a formula of various other chemicals. Tea, or your fruits and veggies, are not involved in this 😉
