Why Just 1% of Japan's Soy Sauce Is Crafted Using This Method But Still Standing

Soy sauce holds a revered position in Japanese cuisine, serving as a vital ingredient that imparts unique flavors to various dishes. Despite its significance, only a mere one percent of Japan's soy sauce supply is crafted through the traditional method of barrel aging. This remarkable technique, deeply rooted in history, involves a painstaking process that transforms raw ingredients into the savory condiment enjoyed globally today.

At the heart of this ancient practice lies the iconic wooden barrel known as "kiyoke." These barrels, meticulously assembled by skilled artisans, have the extraordinary capacity to endure for over a century. Yasuo Yamamoto, a fifth-generation soy sauce maker, stands as a testament to this fading tradition. He is among the few brewers in Japan who handcraft their own barrels, a skill acquired through dedication and passion, as the demand for wooden barrels waned with the advent of industrialization.

The journey of authentic soy sauce begins with the careful selection of crushed wheat and steamed soybeans, which are combined with koji, a vital fungus that initiates the fermentation process. This mixture, weighing over a ton, fills each wooden barrel, accompanied by salt water. The wooden barrels provide an ideal environment for bacteria to thrive, creating the perfect conditions for fermentation. Yasuo and his team diligently stir the soybeans within the barrels, encouraging the growth of beneficial microbes. While the microbes perform the majority of the work, Yasuo's role remains demanding. He monitors the fermentation process daily, relying on his senses to determine the soybeans' progress, a practice honed through years of experience.

This meticulous fermentation process takes at least a year and a half, with Yasuo managing an impressive array of 87 barrels in various stages of development. Each barrel represents a legacy that spans centuries, harking back to the 17th century when these methods were first employed in Japan. However, the landscape of soy sauce production changed drastically during World War II, when resources became scarce, prompting the government to streamline production, reducing the process from years to mere months. This shift led to the rapid modernization of the industry, leaving traditional small-scale businesses struggling to keep pace.

In 2003, Yasuo faced the daunting task of reviving his family's struggling soy sauce business after his father fell ill and had to retire. With determination and perseverance, Yasuo not only had to manage the business but also teach himself various aspects of the production process. One crucial step involved using a press, a skill he mastered to ensure the quality of his soy sauce.

After the lengthy fermentation period, Yasuo transfers the soybean mixture into a pressing machine, extracting the soy sauce slowly over ten days. Unlike industrial counterparts that rush this stage, Yasuo believes that patience is the key to producing a high-quality product. Following this process, some of the soy sauce returns to the barrel, where it mingles with fresh soybeans and wheat for an additional two years, resulting in Yasuo's main product, saishkomi, a darker, more robust soy sauce. This extended fermentation imparts a sweeter aftertaste to the soy sauce, a natural sweetness that industrial brands attempt to replicate by adding artificial sweeteners.

The exquisite balance of umami flavors achieved through this traditional method is cherished by chefs like Hitoshi Kishimoto, who incorporates naturally fermented soy sauce, including Yasuo's brand, into almost every dish served at his restaurant, Koyomi. Kishimoto recognizes the unparalleled depth of flavor that authentic soy sauce brings to his culinary creations.

In Yasuo's quest to preserve the legacy of barrel-aged soy sauce, he conducts barrel-making workshops annually, sharing his knowledge and passion with enthusiasts eager to carry forward this ancient tradition. His dedication extends beyond the boundaries of Japan, as he sells his authentic soy sauce to people worldwide, valuing its cultural and culinary significance. Although priced at a premium, Yasuo's soy sauce offers discerning consumers a taste of history, a testament to the meticulous craftsmanship and dedication that define this time-honored condiment.

In essence, Yasuo Yamamoto's life's mission embodies the essence of tradition and craftsmanship, ensuring that the legacy of barrel-aged soy sauce endures for generations to come. His unwavering commitment not only preserves a culinary heritage but also fosters an appreciation for the artistry and expertise involved in creating one of Japan's most cherished condiments. As the world evolves, Yasuo stands as a guardian of tradition, reminding us of the importance of honoring the past while embracing the future, ensuring that the rich legacy of soy sauce continues to enrich our culinary experiences.