Kosher all year around
Description: Tannin (food colouring)
Function: food colouring
Rationale:
Food-grade tannic acid/tannin is predominantly sourced from oak galls, tara pods or sumac rather than wine grapes, so no clear Stam Yeinom concern by default (STAR-K notes properly-dried grape seeds also lose any wine concern), though grape-seed-tannin variants would need verification.
If you don't see a status above, it does not mean the additive is not kosher automatically - it might just not be documented in our database yet.