History of Soy Sauce
Kishu Yuasa is a birthplace of soy sauce. It has been said that the roots of soy sauce go back to Kamakura era (approximately in 1254). Hottoenmyokushi, the founder of Kokokuji ZenTemple located at Kishu Yura brought back the manufacturing method of Kinzanji miso (Kaizanji miso) from Kaizanji Temple in an ancient China.
Back then, Yuasa had ample supply of natural and clean water, thus Kinzanji miso production flourished. Soy sauce was produced by refining supernatant liquid (called Tamari), which is nutrient-rich liquid naturally created in the process of Kinzanji miso preparation.
Japanese Cedar Barrels
Japanese soy sauce barrels are made of Yoshino cedar trees, and some of those trees are 80 to 130 years old. Each barrel contains roughly 6 tons of liquid (33 koku, 1 koku is approximately 180.39 liters, 6.37 cub. ft.), and 3000 of 1-sho bottles (1.8-liter sake bottle) of soy sauce is prepared. Since a few craftsmen who are skilled to produce these barrels exist in Japan, many of the soy sauce breweries use enameled tanks today. However, Yuasa soy sauce brewery still uses the old-fashioned cedar barrels to manufacture soy sauce.