Written by Mika Tanimoto, Owner-Bartender, Bar Little Happiness — Hiroshima’s specialist whisky & rum bar with 1,000+ bottles
Every distillery has a piece of equipment that tells you what kind of place it is. At Saburomaru, that piece of equipment is ZEMON.
ZEMON is not just unusual. It is, as far as anyone knows, a unique object in the world of whisky — the first pot still ever cast from a zinc-lead alloy, using techniques drawn from a 400-year tradition of Buddhist temple bell-making in the Takaoka region of Toyama Prefecture.
The story of how it came to exist says everything about Saburomaru Distillery and the man who runs it.
The Problem That Became an Invention
When President Takahiko Inagaki began the distillery’s reconstruction in 2016, he faced a fundamental obstacle: the pot stills he needed were simply unavailable. The global whisky boom had created two to three year waiting lists at every major manufacturer. Importing a still from Scotland and waiting for it to arrive would push the distillery’s first release years further into the future.
Inagaki’s response was characteristic. If a copper still couldn’t be sourced from the usual channels, he would make one — using the craft that his home region had been practising for four centuries.
He approached Oigo Seisakusho, a Takaoka manufacturer whose speciality was casting enormous bronze temple bells — structures weighing over 50 tonnes, including bells displayed at the World Athletics championships. Their expertise in large-scale bronze casting was among the most sophisticated in the world. Whisky stills were, to put it mildly, outside their usual brief.
The Science Behind the Alloy
Inagaki did not simply ask Oigo to build something experimental. He conducted research first, working with local public research institutes to demonstrate that a zinc-tin alloy (青銅, bronze) could perform at least as well as pure copper in the distillation process — and potentially better in certain respects.
He also carried out a more hands-on experiment: during the 2017 renovation, working with a limited budget that didn’t allow for a full copper still, he cut sections from a stainless steel shochu still and hammered copper plates to fit the gaps, increasing the spirit’s contact with copper. The results convinced him that the principle was sound. This work was later recognised with an award from the Western Liquor Technical Research Society — the first time a distillery had received it.
ZEMON was cast in 2019. The process was not straightforward. At one point, the massive sand mould used for casting collapsed during the pouring. The craftsmen at Oigo worked through the setbacks alongside Inagaki, who visited the foundry repeatedly to consult on technical details.
What ZEMON Does Differently
The result is a still with properties that no copper pot still can replicate:
Texture: The tin content in the bronze alloy produces a noticeably rounder, smoother spirit than conventional copper stills. Saburomaru describes this as a softer character behind the smoke.
Longevity: Cast bronze is approximately 2.5 times thicker than hammered copper sheet. While conventional copper stills wear through and require replacement, Inagaki has said he expects ZEMON to outlast him.
Efficiency: Bronze’s higher heat retention reduces energy consumption and CO2 emissions by roughly half compared to standard copper stills. Saburomaru filed — and received — Japan’s first whisky industry patent for this property.
ZEMON now sits inside the historic Taisho-era warehouse that forms the heart of the distillery — fitting, as if it had always been there, between the original wooden structural columns with millimetre precision.
The Hiroshima connection: the bronze bells at Hiroshima’s Peace Memorial were also cast by Oigo Seisakusho. There is something quietly moving about that, though Inagaki mentions it only in passing.
Read the full Japanese column: little-happiness.jp/columns/saburomaru-distillery-report-2/
Bar Little Happiness | Hiroshima, Japan
Rum & Whisky specialists | 1,000+ bottles | English menu available
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