This rings especially true if you’re using tea bags instead of loose-leaf herbs. McBride explains that when you crush up herbs to form the small pieces that go into bags, you increase their surface area and expose them to more oxygen, which can dull their flavor. “It’s much less potent because of how it’s stored,” McBride says of herbal tea in a bag.
While it can depend on the type of tea (“true teas” like black, green, and oolong each have their own unique steep times), McBride says you’ll want to let most herbal brews sit for 15 minutes. This should leave enough time for the antioxidant-rich polyphenols, the plant compounds that make herbal teas so healthy, to completely come through in your cup.
After McBride encouraged me to experiment with different steep times, I took to my kitchen and made two identical cups of chai rooibos: one sat for 2 minutes, the other 15. The difference between a quick dip and a longer steep became clear right away.