A few months http://www.arcofamador.org/index.php/glucophage-xr-medscape-ecad.pdf glucophage medscape  The water is heated in a venerable iron pot. The tea pot and cups, are warmed with water and carefully dried. The tea itself, a fine Formosan Oolong from Taiwan, is precisely measured into the pot; the hot water is poured in to cleanse the leaves, and then poured away.