Water for white or green tea, according to most accounts, should be around 80 °C to 85 °C (176 °F to 185 °F); the higher the quality of the leaves, the lower the temperature. Hotter water will burn green-tea leaves, producing a bitter taste. Preferably, the container in which the tea is steeped, the mug, or teapot should also be warmed beforehand so that the tea does not immediately cool down. High-quality green and white teas can have new water added as many as five or more times, depending on variety, at increasingly high temperatures. Recently, green tea (as well as some black teas) have been shown to significantly increase interferon levels in tea consumers, which lends credence to the theory that some teas help boost the immune system.
Photograph Courtesy of Tom Antony (aka Salsero)