In the heart of Japan's Shodoshima Island, a small family-owned business has meticulously crafted a soy sauce that has captivated the culinary world. Yamaroku Tsurubishio Shoyu, a barrel-aged soy sauce, is a testament to the country's rich gastronomic heritage and the unwavering dedication of its artisanal producers.
The Essence of Japanese Cuisine
Soy sauce is the cornerstone of Japanese cuisine, infusing dishes with a depth of flavor that is both complex and harmonious. However, Yamaroku Tsurubishio Shoyu takes this staple ingredient to new heights, offering a sensory experience that transcends the boundaries of the ordinary.
The Yamaroku Legacy
Yamaroku, a company founded about 150 years ago, likely began between the late Edo and early Meiji periods (1868-1912), although the exact date remains unclear due to the lack of records. The company debuted as a soy sauce maker in 1949, transitioning from its earlier role as a "moromi shop," which sold wholesale moromi (soy sauce mash). The third generation of the family introduced a pressing machine to start producing soy sauce.
The Yamamoto family's roots trace back to the Ako domain in Hyogo Prefecture, known for the Chushingura story. They brought their expertise in salt-making, known as "shiohama-shi," to Shodoshima, an island where salt production thrived under the direct control of the Edo shogunate. The family contributed to the island's development, helping Shodoshima's salt become a prized commodity. However, overproduction led to a salt bubble by the end of the Edo period, causing economic decline and severe environmental issues. This hardship prompted the local community to turn to soy sauce production to utilize salt in secondary processing, sparking the growth of the soy sauce industry on the island.
The Art of Barrel Aging
The secret to Yamaroku's unparalleled flavor lies in its meticulous barrel-aging process. Unlike modern soy sauce production methods that rely on high-speed fermentation, the Yamaroku team meticulously ages their soy sauce in traditional wooden barrels for at least three years. This slow, deliberate approach allows the flavors to meld and develop, resulting in a soy sauce that is both complex and balanced.
The Power of Microorganisms in Wooden Barrels
Yamaroku Soy Sauce is entirely made using wooden barrels crafted from cedar, each holding 3,000–6,000 liters. The fermentation process relies on microorganisms like lactic acid bacteria and yeast, which thrive in the environment wooden barrels provide. While using wooden barrels is labor-intensive and challenging for temperature control, the company remains committed to this traditional method for producing the best flavor.
The Living Brewery Home to Microorganisms
Yamaroku's fermentation brewery, built over 100 years ago during the Meiji era, is designated as a national tangible cultural property. Despite its aged appearance, the building’s wooden beams, earthen walls, and floors are home to around 100 types of yeast and lactic acid bacteria. This "living brewery" serves as a vital habitat for the microorganisms essential to soy sauce production.
An Ideal Fermentation Climate on Shodoshima Island
Shodoshima Island's climate, resembling the Mediterranean, is ideal for fermentation due to its warm, dry air and long hours of sunlight. The island's tallest mountain, Kankakei (817m), absorbs heat and generates a unique warm, dry wind. This exceptional climate creates optimal conditions for the yeast and lactic acid bacteria needed in soy sauce production.
Yamaroku's Exceptional Umami Levels
Soy sauce umami is typically measured by nitrogen levels, which primarily come from soybeans. Higher nitrogen levels indicate stronger umami, usually around 1.2 for light soy sauce and 1.5 for dark soy sauce. Yamaroku's Tsuru-bishio soy sauce, however, boasts an umami level exceeding 2.3, far surpassing standard varieties.
Balancing Low Sodium with Rich Umami
While increasing umami is technically straightforward—using additives, finely crushed soybeans, or shorter aging processes—true flavor complexity involves more than just numbers. Qualities like richness, smoothness, and the harmony of umami, spice, bitterness, sweetness, and aroma define the overall taste, which cannot be fully captured by metrics.
Prioritizing Flavor Over Numbers
Although Yamaroku’s soy sauce may appear inconsistent when judged by numerical standards compared to mainstream brands, the company values the nuanced human perception of taste. Their philosophy emphasizes creating soy sauce that delivers "deliciousness and happiness," valuing the joy it brings over simple measurements.
Flavor Profile: Rich Depth and Smoothness
Yamaroku Soy Sauce’s Tsuru-bishio is their proud creation, crafted to achieve unparalleled richness and smoothness. Using a double-fermentation method (saishikomi), soy sauce aged for 1–2 years is returned to the barrel, where soybeans and wheat are added instead of salted water. This mixture ferments naturally for another 2–3 years.
By doubling the ingredients and allowing ample time for natural aging, the process enhances the flavor and aroma, utilizing the rounded salinity of the aged soy sauce instead of raw salt. The result is a soy sauce with a profound depth, delicate smoothness, and rich aroma that spreads beautifully in the mouth.
Enter the world of Shoyu
In a world that often prioritizes speed and efficiency, the Yamaroku team stands as a beacon of tradition and craftsmanship. Their unwavering dedication to the art of soy sauce production has resulted in a product that is not merely a condiment, but a true culinary masterpiece. By preserving the time-honored techniques of their ancestors, Yamaroku Tsurubishio Shoyu invites us to slow down, savor, and appreciate the depth of flavor that can be found in the most humble of ingredients.
