This jar is called “Chaire,” meaning tea caddy. It is used during a tea event, (tea ceremony, an unfortunate translation in my opinion). There are two kinds of tea caddy used during an event. They are called “Natsume” and “Chaire.” Natsume is used to keep macha for usu-cha, (thin tea at an event) and it is made of wood lacquered or without. Chaire is used to keep macha for thick tea at an event, and it is made of pottery. Neither is used to store the powdered tea, macha, instead to keep just enough quantity during an event. There is a ranking of the importance or stature among tea utensils, and Chaire enjoys a very high rank.
Among Chaire, there are about 13 kinds of shapes -smaller, bigger, rounder- within a particular size restriction. All have a lid made out of ivory, and the inside of the lid is covered with gold leaf. Why gold leaf? The tradition was started to make sure that the powdered tea was not poisoned! Well, the way of tea was established around 1600, when assassination among powerful warlords and worriers were common.
This particular Chaire is from the early to late 1600s. The shape belongs to “Katatsuki” style, which means it has a pronounced shoulder near the neck. It is “Yakishime” pottery: high-fired, unglazed ceramic. Among the highly ranked Chaire, connoisseurs especially desire ones from this period.