Kettle
Definition
A vessel for heating water for tea, ranging from electric variable-temperature kettles to traditional cast-iron tetsubin and charcoal-fired silver and clay kettles. Choice of kettle affects water temperature control and, some argue, water character.
Why it matters
At the most basic level, a kettle is any vessel used to heat water for tea. In specialty tea, the choice of kettle becomes meaningful for both practical and sensory reasons. Variable-temperature electric kettles are now standard for everyday brewing, offering precise control over the water temperatures required for delicate greens (around 70 to 80 degrees Celsius), oolongs (85 to 95 degrees Celsius), and black or pu-erh teas (95 to 100 degrees Celsius). Traditional Japanese tetsubin cast-iron kettles are valued in chanoyu and in modern gongfu setups for their heat retention and, when used over charcoal, for a perceived softening effect on water. Silver kettles, ceramic kettles, and charcoal-fired clay kettles are used at the top end of gongfu practice. Whether these noticeably change the water is debated, but their ritual and aesthetic role in serious sessions is undeniable.