This Tokoname-yaki yuzamashi (湯冷まし - water cooler) has a wide opening, providing a large surface area for the water to cool quickly. It is made from Tokoname kokudei (黒泥) clay, which has the same properties as the iconic red shudei (朱泥) but is fired in reduction producing a deep black. This pot has a striking yōhen (窯変) gradient from a rich red to a deep black. Yōhen, which means "changed by the kiln", refers to the attractive gradient from bronze to black across the piece caused by specific firing conditions.
Yuzamashi are used to cool down boiling water to a temperature more suitable for brewing green tea. When poured into a yuzamashi, boiling water cools to roughly 90°C, which then will cool to roughly 80°C when poured into a cold teapot. To cool water further, you can either let it sit in the yuzamashi for longer, or pour it into cups and then into the teapot.
This piece was made by the workshop division of the highly-respected Gyokko (玉光) Kiln, which uses a different kanji spelling of Gyokko as their stamp: 玉香
Width: 17 cm (6.7 in)
Height: 7 cm (2.8 in)
