Brand spotlight

Yamaroku Shoyu

Four-year shoyu alive in cedar barrels

Shodoshima’s Living Fermentation Heritage

Shodoshima has made soy sauce for centuries, and Yamaroku Shoyu protects one of its rarest methods: fermentation in kioke cedar barrels. Only about one percent of Japanese soy sauce is still brewed this way. The microorganisms living in the barrels, beams, walls, and earthen floors give each batch a flavor that cannot be replicated in steel. Yamaroku received a 2025 Sustainable Japan Excellence Award for reviving the endangered barrel craft.

Yamaroku Shoyu fifth-generation brewer Yasuo Yamamoto

Yasuo Rebuilds the Barrels Himself

Fifth-generation brewer Yasuo Yamamoto returned to his family’s roughly 150-year-old brewery and saw that the future of its soy sauce depended on the future of kioke. With only a few barrel makers left, he apprenticed in the craft and began building barrels himself. He now shares those skills through a national revival project, working so his children’s generation can inherit both the brewery and the living tools that define it.

Double Brewed, Four Years, Living Wood

Tsurubishio is a saishikomi, or re-brewed, soy sauce. A dark shoyu is aged for two years, then used in place of salt water for a second mash that ferments another two years. Century-old cedar barrels host native yeast and lactic-acid bacteria, creating deep aroma, rounded umami, and a mellow finish. Yasuo oversees the process year-round, allowing time and the brewery’s microbial ecosystem to do the essential work.

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JAPAN 🇯🇵
JAPAN 🇯🇵

Tsurubishio Soy Sauce (Barrel aged 4 yrs)

$36.99
$36.99