Banko Ware: The Donabe Town That Imports Its Secret Ingredient

If you own a Japanese clay pot, it is probably from Yokkaichi. Not from the famous kilns — not Iga, not Shigaraki, not anywhere with a Momoyama tea-ware pedigree — but from an industrial port city in Mie Prefecture that most visitors to Japan pass through on the train without looking up.

Banko ware makes around eight of every ten donabe produced in Japan; the national craft bodies put the figure between eighty and ninety percent. It is, by volume, one of the most successful pottery traditions in the country, and one of the least talked about. And the thing that made it successful is not a local clay, or a kiln technique, or a lord’s patronage. It is a mineral that has to be shipped in from the other side of the world — and that the electric-car industry has recently started outbidding everyone for.

A wish, stamped on the bottom

The name comes from a merchant’s optimism. Nunami Rōzan was born in 1718 into a Kuwana shipping family — wealthy, educated, deep into tea — and somewhere between 1736 and 1740 he built a kiln at Obuke, in what is now Asahi Town. He made tea utensils, largely for his own satisfaction, with a decorative sense that borrowed cheerfully from abroad: Dutch lettering, foreign animals, bright overglaze reds in the Kyoto manner.

On the underside he stamped banko fueki (萬古不易) — roughly, eternal, unchanging. It was a wish that his work would last forever. It is now the name of an industry that employs a city, which is a stranger way for a wish to come true than he can have imagined.

Rōzan died in 1777 and left no successor. The kiln went cold, and stayed cold for about half a century.

The man with the wooden moulds

What restarted it was not reverence but a good idea about production. In the Tenpō era (1830–1843), the Kuwana potter Mori Yūsetsu (1808–1882) and his brother Senshū revived the name — and Yūsetsu brought with him a way of forming teapots in hinged wooden moulds rather than throwing each one on the wheel.

This is the part that matters. Kata-banko, mould-formed Banko, made pots that were thinner, lighter, more consistent, and far faster to produce than wheel work allowed. It arrived exactly as sencha drinking was spreading through the merchant class and everybody suddenly wanted a small teapot. Kuwana domain encouraged the trade; Yūsetsu Banko, with its soft pink enamels and painted scenes, became a regional specialty.

A tradition founded by a gentleman amateur was reborn as something closer to a manufacturing method. Banko has been that ever since.

”If you’re broke, go see Yamanaka”

The third founder is the one worth remembering. Yamanaka Chūzaemon (1821–1878) was the village head of Suenaga, near Yokkaichi — flood-prone land, a lot of poor farmers, a bad stretch of decades at the end of the Edo period. He had been captivated by Mori Yūsetsu’s work since youth, and in 1853 built a small kiln at his own house to copy it.

He spent more than twenty years at it. In 1870 he opened a full-scale kiln, and then did something unusual with it: he taught the process to the unemployed, the poor and to housewives, lent them the clay and the tools, and bought their output even when it came out badly, using the purchase as an occasion to correct the work. The local saying was that if you were in trouble for money, you went to see Yamanaka.

That is why Banko is structured the way it is. It was deliberately built as a distributed cottage industry — many small workshops, divided labour, employment as the actual objective — rather than as a handful of prestige kilns. Over a hundred Banko-related businesses still operate in and around Yokkaichi today.

The purple teapots

Meiji Banko’s signature product was the shidei (紫泥) teapot, and it exists because the industry ran out of something.

By the middle of the Meiji era the white clay the potters had been using was exhausted. What was left in the ground was an iron-rich red clay, so they used that instead: thrown on the wheel, left unglazed, and fired in a reducing atmosphere, where the iron turns a dark purplish red-brown. Hence shidei — purple clay. Unglazed, the surface stays faintly absorbent, and it takes on a low, oily sheen the more tea passes through it.

Banko teapot makers, and the national craft body, hold that the iron in the body interacts with the tannins in sencha and softens the astringency of the tea. It is an old and widely repeated claim across Japan’s unglazed-teapot traditions, and there is some published work behind it, but treat it as the region’s considered opinion rather than as settled fact. What is not in doubt is that an unglazed pot changes with use, and a glazed one does not.

See also: Tokoname and the red-clay kyusu, and how to choose a kyusu.

1959: the pot that stopped cracking

Then the donabe.

Clay pots are old; clay pots that survive a hard life are not. The failure mode of earthenware over a flame is thermal shock — the body expands unevenly, and it cracks. Around 1959, the Banko industry solved this by blending petalite into the clay body. Petalite is a lithium aluminium silicate. Fired, it converts to crystalline phases that barely expand when heated, and a body loaded with them can take temperature swings that would split ordinary earthenware.

The proportions are not a garnish: the standard Banko donabe body runs around forty percent petalite, and the glaze can run higher still. Firing is typically around 1,150–1,200°C.

This is the whole commercial story of postwar Banko. Iga sells heat retention, off the porous clay of an ancient lakebed. Banko sells a pot that does not break — a flame-safe donabe cheap enough and tough enough to be the default in an ordinary kitchen, used every winter for decades. Eight out of ten. Yokkaichi Banko ware was designated a national Traditional Craft on 12 January 1979, with a production area spanning Yokkaichi, Kuwana, Suzuka and Inabe cities and the towns of Tōin, Komono, Asahi and Kawagoe.

The awkward part

Petalite is not mined in Japan. Much of what Yokkaichi used came from Zimbabwe — and lithium is now the most contested industrial mineral on earth, because it goes into electric-vehicle batteries.

By 2023 the supply had tightened badly. Reporting from the region describes a Zimbabwean mine that had been a key source being acquired by a Chinese company, Japanese trading houses unable to renew contracts, and prices rising to more than five times earlier levels. In October 2023 the Banko ceramics industry cooperative formally petitioned the governor of Mie Prefecture for support and for intensified research into substitutes. The prefecture’s own industrial research institute has worked on lowering the petalite ratio and on alternative raw materials, and some Yokkaichi firms have already brought products made with substitute materials to market.

Nobody in Yokkaichi is predicting the end of the donabe. But it is a genuinely odd position for a traditional craft: the single ingredient that defines the modern product is imported, finite, and wanted by an industry with vastly deeper pockets. The clay under Mie is still there. The rock that makes it survive a flame is the part in question.

Which is, in its way, consistent. Banko has never been a craft about a sacred local material. It was a rich man’s hobby, then a mould-making innovation, then a poverty-relief scheme, then a materials-science fix. It keeps solving a practical problem with whatever is to hand, and the name on the bottom of the pot is a wish for permanence stamped by someone who had no idea what would be asked of it.

Living with a Banko pot

The practical notes, briefly:

A Banko donabe is tough, not invincible. Petalite buys you shock resistance, not immunity. Dry the outside before it goes over the flame, don’t heat it empty, and don’t set it down hot on a cold wet surface.

Season it once anyway. The body is porous, and medome — cooking a thin rice porridge in it before first use — seals the pores so it won’t weep or take on odours.

Gas or open flame unless marked otherwise. Most donabe are not induction-compatible; IH-safe models say so explicitly and have a metal plate built in.

Go easy on detergent. Porous clay holds the smell of soap. Water, and baking soda for anything stubborn, is usually enough — then dry it completely before it goes in the cupboard.

For the full method, including why leftover rice works better than rice-rinsing water: Donabe — choosing and breaking in a Japanese clay pot. Or browse hand-picked, Japan-shipped flameware on The Table.

Sources & Further Reading

• YOKKAICHI BANKO Yaki (Ceramics) — Traditional Crafts Aoyama Square — The national traditional-crafts body: the designation of 12 January 1979, the eight-municipality production area in Mie, the banko fueki stamp, reduction-fired shidei teapots, and firing at roughly 1,180–1,200°C.
• Yokkaichi Banko Ware — KOGEI JAPAN — The craft-industry portal on Banko’s eighty-to-ninety percent share of Japan’s donabe production, the roughly forty percent petalite blend, and the iron-and-tannin claim for shidei teapots.
• About Banko-yaki — Banko no Sato Center, Yokkaichi — The local Banko hall, in English: Nunami Rōzan’s dates and 1736–40 kiln, the Mori brothers’ kata-banko wooden moulds, Yamanaka Chūzaemon’s mass production, the 1959 petalite development, and the 100-plus businesses in the area today.
• 萬古焼原料不足に支援を — Chunichi Shimbun — The regional paper on the Banko ceramics cooperative’s 2023 petition to the governor of Mie for research into petalite substitutes, and the follow-up on the Zimbabwe supply disruption and the industry’s move toward alternative materials.