Written by Mika Tanimoto, Owner-Bartender, Bar Little Happiness — Hiroshima’s specialist whisky & rum bar with 1,000+ bottles
There is a cooperage inside Saburomaru Distillery. It is called Re:COOPERAGE, and it is one of the most important things in Japanese whisky that almost nobody knows about.
The Barrel Crisis in Japanese Whisky
President Inagaki talks about barrels differently from most distillery operators. For him, a barrel is not a container. It is a raw ingredient — one that determines the majority of a whisky’s character, and one that is currently in crisis.
In the world of whisky, barrel quality has deteriorated significantly over the past decade. Where leakage rates once ran at around 1%, they have climbed toward 10% as global demand has overwhelmed supply chains and pushed marginal-quality casks into the market. Meanwhile, Japan has fewer than 100 trained coopers in the entire country.
Inagaki’s response to this — predictably — was not to simply complain about the situation. It was to build something.
The Cooper Who Came from Kagoshima
Re:COOPERAGE employs a young cooper who trained in Kagoshima at a shochu producer before being placed at Saburomaru by his mentor — a legendary craftsman who recognised Inagaki’s seriousness and trusted him with his most talented apprentice.
The cooper is in his twenties but already has ten years of experience. Working alone, he restores between 70 and 120 barrels per month — not just for Saburomaru, but for other distilleries across Japan. The facility is deliberately open to the wider industry. That is the point.
Gama: The Weed That Seals the Barrels
Whisky barrels use no nails and no adhesive. The staves are held together by hoops, and the joints between them are sealed with a plant material that swells when wet, preventing leaks. In traditional coopering, this material is bulrush — known in Japanese as gama (ガマ).
Saburomaru’s cooper spent a year searching Toyama for a local source of gama that met his requirements. He eventually found it growing densely on land whose owner was delighted to have someone clear what they considered a nuisance weed. The coooper now harvests, washes and dries it himself. Every barrel sealed at Re:COOPERAGE is sealed with Toyama bulrush.
BarrelRoll 2: Another Inagaki Invention
The work of restoring a barrel once involved scraping the inside by hand — backbreaking, dusty work with a daily maximum of two barrels per person. Inagaki designed an automated barrel-sanding machine called BarrelRoll 2, taking inspiration from washing machine mechanics and the automated wok-tossing machines he had seen in Chinese restaurants.
After BarrelRoll 2 was installed, throughput increased to 16 barrels per day. When I stood in front of it and was asked if I had any questions, I could only say I had never seen anything like it.
“Of course you haven’t,” Inagaki said, clearly pleased. “I invented it.”
The finished barrels — those that have given everything they can to whisky maturation — are sent to the distillery’s attached restaurant, Kamado Saburo, where they are burned as fuel for the kamado (traditional clay cooking stove) that cooks the rice. Nothing is wasted.
Read the full Japanese column: little-happiness.jp/columns/saburomaru-distillery-report-3/
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