Tenmoku glaze sake cup by Okada Yu

Width: 7.3cm Height: 5.6cm

Tenmoku glaze sake cup

-- Created by Masaru Okada --

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Work summary

This Tenmoku-glazed sake cup was made by Okada Masaru, who has a kiln in Uji-tanzan, Kyoto, and is renowned for his research into black glazes and kiln-change expressions. Based on a straight cylindrical shape, it is slightly tapered at the waist and features a form that gently bulges toward the bottom. Countless tiny oil crystals are scattered on the astringent indigo-colored Tenmoku glaze, giving it a depth and brilliance reminiscent of a quiet night sky. A purple-brown color reminiscent of a scarlet sash permeates the rim, adding a warm aftertaste to the darkness of the black glaze.

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Glaze and technique

A small amount of cobalt oxide and manganese oxide is used in combination with the iron feldspar-based Tenmoku glaze , giving the piece a metallic luster of blue-black color with a black base.

Three-stage firing: primary reduction → slight oxidation → rapid cooling . By "oscillating firing", reduction and oxidation are alternated finely, and oil-droplet-shaped iron crystals are precipitated on the surface.

The scarlet rim is achieved by increasing the oxygen supply slightly towards the end of the firing process, causing the iron to oxidize and form a thin purple-brown film.

The glaze has a satin-like semi-gloss finish. From a distance it has a calm matte look, but as you get closer a metallic glow emerges, changing its appearance depending on the distance and light source.

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Historical and cultural background

Tenmoku glaze originated from the black-glazed bowls of Jian kiln in Fujian Province during the Song dynasty. It was introduced to Japan by Zen monks during the Kamakura period and developed as a highly valued item in the tea ceremony. The highly random crystal scenery, such as oil droplets and Yohen, is highly regarded as the "miracle of kiln transformation" and continues to fascinate artists today. The highlight of this work is that Okada Masaru has applied his many years of accumulated know-how in kiln transformation control to preserve the mysteriousness of classical Tenmoku while adding a modern nuance of indigo steel color.

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Aesthetic intent and spirituality

The oil crystals scattered in the indigo-colored darkness evoke the view of the infinite universe, reminiscent of the Zen phrase "Yashokumuhen." Meanwhile, the curved body symbolizes "Kashuku" - the inhalation and exhalation of breath - imprinting the rhythm of life onto the vessel. Every time sake is poured and the cup is swirled, the crystals sparkle like a nebula, and when the sake is downed, the scarlet rim faintly appears, creating an aftertaste of a once-in-a-lifetime encounter.

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How to use and points to note

Suitable for chilled or room temperature sake : The cylindrical shape retains the aroma, while the indigo steel color brings out the transparency of clear sake.

Lighting effects : Daylight LED lights bring out the metallic blue steel light, while incandescent lights make the oil droplets glow a soft silver-gray. Enjoy the multi-layered scenery by changing the lighting.

A pleasure to hold : The narrow design creates a natural grip for your fingers, and the thin, lightweight construction makes it easy to hold.

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This sake cup, with its deep blue steel light and serene oil droplet crystals, is a condensed version of Okada Masaru's aesthetic of "controlled chance." We hope you will hold it in your palm and enjoy the fleeting universe depicted by the light and sake.