Yamaju Masuda Shoten 2026: Inside a 130-Year-Old Katsuobushi Workshop in Yaizu Shizuoka

Shizuoka · Yaizu · Craft

Yamaju Masuda Shoten 2026: Inside a 130-Year-Old Katsuobushi Workshop in Yaizu

A small family workshop in Yaizu still smoking bonito over open fire. The umami in your dashi most likely starts in a workshop like this.

A craftsman at one of the workshop’s steaming stations. The whole place runs on steam, fire, and routine — most of it unchanged since the Meiji era.

I went to Yaizu on a weekday morning. The town sits on the Suruga Bay coast, about an hour west of Shizuoka, and has been Japan’s bonito processing capital since the Edo period. The workshop I came to see is small — a family operation called Yamaju Masuda Shoten, founded in 1887 — and it is one of the very few places left in the country that still makes katsuobushi using tebiyama-zukuri, the original direct-fire smoking method. I wanted to see how the umami in every Japanese kitchen actually gets made. The workshop runs on steam, smoke, and four generations of muscle memory.

Quick Facts

Why Yaizu, and Why This Workshop

Yaizu has been a fishing port for centuries. The deep waters off Suruga Bay give the city access to skipjack tuna (katsuo) almost year-round, and the local processing industry grew up around that. At one point in the 1800s, dozens of small katsuobushi workshops ran in Yaizu. Most are gone now — replaced by larger industrial operations or shuttered when the next generation didn’t take over.

Yamaju Masuda Shoten is one of the holdouts. It was founded in 1887 by Masuda Tasaburo and has been continuously operated by the Masuda family since. The current operation is small, deliberate, and stubbornly traditional. It still uses the smoking method called tebiyama-zukuri — direct fire, no flue gas, oak and cherry firewood — which most of the industry abandoned because it is slower and more expensive.

The main factory floor. Steam, smoke, and tin-sheet roof. The acoustics are mostly drips and the soft scrape of an iron rack on stone.

The Process, Step by Step

From whole skipjack to finished katsuobushi takes roughly three to four weeks for arabushi, and up to six months for the fully aged hongare-bushi. The workshop runs the early stages every working day. Below is what I saw, in order.

Step-by-step

From whole bonito to finished katsuobushi

01

Sorting and gutting. The bonito arrive whole at the workshop, generally caught off the Pacific coast. They are sorted by size and gutted on metal trays.

02

Boiling. Each fish is simmered in a deep iron pot for roughly an hour. This sets the protein and locks in the umami compounds before any smoking begins. The boiling-water vapor is the first cloud you see when you walk in.

03

Filleting and bone removal. After cooling, each fish is split into four loins and the major bones are pulled by hand. The pin-bones are picked individually with tweezers. This is the only stage where the work is slow and quiet.

04

The first smoke. The loins go onto wooden racks above the smoke chamber. The fire is fed with split oak and cherry, and the smoke is deliberately heavy. This first smoking — called baikan — runs for about half a day.

05

Cooling, sleeping, repeating. After the first smoke, the loins rest on racks for hours, then go back into the smoker. This cycle repeats — typically 10 to 20 times — over the course of about two weeks. With each pass, the loin loses water, the surface darkens, and the umami concentrates inward.

06

Surface trim and inspection. The half-finished loins — at this stage called arabushi — get checked and trimmed. The blackened, hardened surface is cleaned and a small amount of charred wood is scraped away. This is the cheaper grade and the form you’ll find shaved into most everyday dashi packets.

07

Mold curing — three rounds. For the fully aged grade — hongare-bushi — the arabushi is moved to a humidity room and a controlled mold is applied. Over weeks, the mold pulls remaining moisture out and develops complex flavor. The mold is brushed off, and the cycle is repeated up to three times. The final product is rock-hard, almost wood-like.

08

Aging and shipping. Hongare-bushi is left to rest for additional months before shipping to high-end restaurants and home cooks who shave it themselves with a wooden plane. Yamaju ships nationwide direct from the workshop.

The Tools

The three knives one of the craftsmen showed me. Filleting, pin-bone, and surface-trim. Sharpened daily.

Most of the work runs on hand tools — long filleting knives, pin-bone tweezers, the surface-trim knife with its thick spine. The craftsmen sharpen them every morning. The wooden bench they sit on is older than the men using it.

The smoke chamber itself is the largest piece of equipment in the building. It’s a brick-lined pit with iron grates above, a fire bed below, and a chain hoist that lowers the racks down. There’s no automated control. Heat is judged by sight and the back of a hand.

Why Tebiyama Matters (For Eaters)

If you cook Japanese food at home, the difference between commodity katsuobushi and tebiyama-style katsuobushi is real and noticeable. The mass-produced flake is smoke-flavored, sometimes lightly. A tebiyama flake is genuinely smoky — closer to a single-malt whisky compared to a blended one.

The reason has to do with the smoke chemistry. Direct-fire smoke contains phenolic compounds and combustion volatiles that don’t make it through industrial flue systems. Most of those compounds are not flavor-active in their own right, but they react with the bonito’s amino acids over the repeated heat cycles to develop the deep umami-and-smoke complexity that defines a great dashi.

Once you have shaved a hongare-bushi yourself with a wooden plane and made dashi from it, supermarket pre-shaved flake will taste flat. This is the trap of every traditional craft — the moment you understand it, the cheap version stops being satisfying.

Two craftsmen working at the same smoking station. The work is repetitive, methodical, and largely silent.

How to Visit: The Tour Logistics

Getting to Yaizu

What to Bring

After the Tour: Where to Eat

Yaizu is a fishing town. The katsuo / bonito sashimi served fresh at local restaurants is some of the best in Japan, especially in spring (hatsu-gatsuo) and autumn (modori-gatsuo) seasons. A quick walk from the station puts you in the Sakanacenter wholesale market complex with multiple sashimi-bowl restaurants.

Combine This Trip With

Frequently Asked Questions

Final Thoughts

Two craftsmen at the trim and inspection bench. The third generation of the Masuda family at the same workshop, doing the same work.