Literally meaning hot water cooler in Japanese, the yuzamashi is used to temper the water before pouring it into the teapot so as not to burn the delicate green tea leaves such as those of gyokuro, kabusecha or sencha. It was produced in Tokoname. It is made of unglazed raw earth. It also has a stainless steel grid with very fine holes that allow it to be used as an open teapot or a water cooler. I also use it as an intermediate container, the equivalent of a jug in the gong fu cha, to homogenize the infusion made in the kyusu teapot with a lid that I pour into the yuzamashi before pouring into the bowls.
Tokoname is a small coastal town in Japan near Nagoya that has specialized in pottery production for centuries. In just a few decades, it has become a major producer of high-quality teapots and teaware. There are several teapot factories in Tokoname, but there are also around fifty independent potters producing some of the finest tea ceramics.