Akitsu clay, now a phantom clay
Tozo Watanabe
Akitsu Mumyoi, a clay that no longer exists
Mumyoi from Sado Island traditionally blends two natural clays: "Nosaka", a very sticky yellow clay from the Nosaka settlement near the Aikawa gold mine, and "Mumyoi", a red, low-plasticity clay from inside the mine and the hills around it. Akitsu Mumyoi instead uses clay from an area called Akitsu, combined with the yellow Nosaka clay. Akitsu is where Sado Airport now stands, in Ryotsu. It lies right beside the brackish Lake Kamo, at the foot of the Osado mountain range and downstream of Mount Kinpoku, the highest peak on the island. Sado Airport has already been built over the ground where this Akitsu clay was dug, so no more clay of the same quality can be taken. Long before the airport was constructed, clay obtained by Mr. Tozo Watanabe was stored in a warehouse.
When he created test pieces and we conducted tests, it turned out to be exceptionally good clay. However, Akitsu clay has low plasticity, so it is hard to make pottery from it alone, and the Akitsu Mumyoi series is made by adding Nosaka clay, which has high plasticity. Production of Akitsu Mumyoi ends when the stock of clay runs out.
Lake Kamo
Raw Nosaka clay
Winter at Lake Kamo
Three different firings
Akitsu Mumyoi comes in three versions.
All three are made from the same clay, and the firing changes how they look. It changes more than the look: the effect the clay has on the taste of the tea differs as well.
Body: oxidation firing > reduction firing > carbonized reduction firing, in that order
Aftertaste (finish): carbonized reduction firing > reduction firing > oxidation firing, in that order
Remains of the old Aikawa gold mine
The Osado mountain range
Akitsu shudei tasted very well and was never used for teapots
Akitsu clay used to be fired into roof tiles, while teapots were made almost entirely from Aikawa clay, the Mumyoi dug around the Aikawa gold mine. In the Japanese ceramics trade, clay is usually chosen on fired color, appearance or historical reputation rather than on its relationship with taste. That is why a clay nobody had paid attention to occasionally turns out, as here, to be excellent for flavor.
After repeatedly firing samples and testing for flavor to optimize the blend ratio of Nosaka and Akitsu Mumyoi clay and the firing temperature, we were able to achieve optimal results in both texture and flavor of the fired product.
Even now, a small amount of Akitsu raw clay remains near Sado Airport.