Does flavored tea need a hechsher?

Answer: Yes.

Reason: Only plain black and green tea is exempt. Flavored teas (e.g. Starbucks strawberry green tea) need a hechsher.

Source:

• cRc: flavored tea requires kosher certification (“flavors are kosher sensitive”). Earl Grey with bergamot oil is fine without; with bergamot flavor it needs certification.
• Star-K: any tea with natural or artificial flavoring requires certification.

Related questions:

• Does plain black or green tea need a hechsher? No.
• Does flavored coffee need a hechsher? Yes.

More from Rabbi Tahan: Q&A: Hechsher on Tea · Q&A: Hechsher on Herbal Teas

References: cRc (askcrc.org), “Flavored tea” · cRc (askcrc.org), “Tea, including decaffeinated” · Star-K, “The Kashrus of Tea – With No Strings Attached!”