An investment in a good kettle is essential for a serious tea drinker. While water may be heated in a microwave, the process robs the liquid of oxygen, badly affecting the flavor of your tea. A stovetop kettle or electric kettle will both heat water quickly and reliably. Glass kettle offers the advantage of lower cost and the visual splendor of watching water boil. An electric kettle, on the other hand, offers the advantage of speed as well as precise temperature settings.