A tisane (or ptisan) is any herbal infusion other than from the leaves of the tea bush (Camellia sinensis). The English word “tisane” originated from the Greek word πτισάνη (ptisanē), a drink made from pearl barley.
Tisanes are made with fresh or dried flowers, leaves, stems, seeds or roots, generally by pouring hot (not boiling water) over the plant parts and letting them steep for about 10 minutes. Tough stems, seeds and roots must be boiled on a stove after being mashed. The tisane is then strained, sweetened if so desired, and served.
Some products labeled as “herbal teas” are true tisanes and some are not. Some “herbal teas” do not contain leaves from the tea bush and are therefore true tisanes. Why they are called “herbal teas” when they contain no tea I couldn’t say and is misleading. The only commonality tisanes and teas share is their preparation for drinking and this could be where the cross-over occurred. Other mixtures labeled as “herbal teas” do contain leaves from the tea bush and have been combined with herbal plant materials, hence the addition of “herbal” before the word “tea,” so be sure to check the ingredients. Real tea contains caffeine and if you are limiting your caffeine intake, knowing whether you are consuming a tisane or tea is important.
Many blends of real tea are prepared by adding other plants to an actual tea (black, oolong, green, or white tea); for example, the popular Earl Grey tea is black tea with bergamot added, Jasmine tea is Chinese tea with Jasmine included, and Genmaicha is green tea combined with roasted rice. Such preparations are varieties of tea, not tisanes.