Handmade Mashiko Chawan Bowl - Kaiyūryū

Mashiko Chawan Bowl - Kaiyūryū 灰釉流

“灰釉” (Kaiyū) refers to a glaze made primarily from ash derived from plants, grasses, or straw. Ash contains alkaline components such as sodium and potassium, which, when fired at temperatures above 1200°C, melt the feldspar in the clay body to create a glassy surface, producing natural flows and colors. This technique intentionally reproduces the ancient “natural glaze” effect, where ash falling into the kiln during firing would melt onto the pottery.

It has been used in Japan since the Nara and Heian periods. The type of ash (pine, oak, chestnut, straw, etc.) affects the color and texture, resulting in a rustic yet deeply expressive appearance. The term “流” (ryū) refers to the flowing movement of the glaze.

灰釉流 thus describes a technique designed to emphasize the natural dripping or flowing appearance of ash glaze.

What is Mashiko ware?

Mashiko ware is a traditional Japanese pottery produced in and around Mashiko, Tochigi Prefecture. It began in the late Edo period when Otsuka Keisaburō established a kiln there, bringing techniques from Kasama ware (in present-day Ibaraki Prefecture). 

Its characteristics include a warm, earthy tone due to high iron and silica content in the local clay, along with a robust, tactile texture and durability suitable for daily use. Mashiko ware is known for its simple, functional design.

※Do not put in microwave or dishwasher.