In Thailand we make an herbal infusion drink from the sepals and calyces of the flowers of the roselle plant, a type of hibiscus. The dried flowers are boiled in water for 8 to 10 minutes, making a bright red drink that has a sour, tart flavor that many people say is similar to cranberry. While it can be served as an invigorating hot tea, most people like it as an iced drink with lots of sugar. Known here as Nam Krajieb, Thais consider it a healthy drink that is used for treating loss of appetite, colds, heart and nerve diseases, upper respiratory tract pain and swelling and inflammation, fluid retention, stomach irritation, and disorders of circulation; for dissolving phlegm; as a gentle laxative; and as a diuretic to increase urine output. Some researchers think that chemicals in hibiscus might be effective in treating certain conditions, although the scientific data has been inconclusive.
The drink is quite simple to make, and will add an authentic flair to your next Thai meal.