Tetsubin is a Japanese cast iron pots with a pouring spout, a lid, and a handle on the top. It is used for boiling and pouring hot water for drinking purposes, such as for making tea.
Tetsubin are traditionally heated over a charcoal fire. Tetsubin are often elaborately decorated with relief designs on the outside. They range widely in size, and many have unusual shapes and are therefor popular with collectors. A relatively small tetsubin may hold around .5 litres of water while large ones may hold up to 5 litres.
The historical origin of the tetsubin is not certain. At least one authoritative Japanese source states that it developed from the spouted and handled water kettle called tedorigama that was already being used in tea ceremony during the 15th century in the era of Sen no Rikyu (1522–91). During the 19th century, infused tea became more popular and tetsubin were considered primarily status symbols rather than functional kitchen items.
There is also a kind of relatively small cast iron pot that resembles a tetsubin but is glazed with enamel on the inside in order to lend itself to making brewed tea, and is referred to as an iron kyusu or teapot.
It is not clear when the first tetsubin pots appeared in Japan, but a hypothesis is that the popularity of the tetsubin pot grew alongside with sencha green tea. China introduced Japan to sencha around the middle of the 17th century. Throughout the 18th century, people started drinking sencha as an informal setting for sharing a cup of tea with friends or family. With the rising popularity of sencha also the popularity of the tetsubin grew. Tea pots similar to tetsubin are tedorikama, toyama, mizusosogi, dobin, and yakkan. The yakkan is the very similar to the tetsubin with the main difference that the yakkan is made from copper whereas tetsubins are traditionally made out of cast iron. During the 19th century, tetsubin designs went from simple basic iron kettles, to elaborately engraved masterpieces.