Soy Sauce, A Magical Elixir

Sixty-seven wooden barrels, linked by ropes made of bamboo, so high that they reach the ceiling. Kazuhiro Shibanuma cares for them with extreme care, as required of the leader (17th generation) of Shibanuma Soy Sauce, who have produced this species for more than 330 years in Tsuchiura, Ibaraki Prefecture.

He tells us that these barrels have been used continuously for more than 150 years. “This is where we ferment our soy sauce,” explains Shibanuma. “These barrels are said to last 300 years, and each one contains a slightly diverse mix of microorganisms. Our expert fermenters are familiar with the details about the microbes in each barrel, so they know how hard to shake the mix and How far has the fermentation advanced? Famous for its abundance of fresh water, Ibaraki has a long tradition of growing high-quality soybeans and wheat. The area’s lakes and rivers also facilitated the transportation of goods to Edo (Old Tokyo), making soy sauce a regional specialty since the Edo period (1603–1867).

“Japanese soy sauce is characterized by the umami that is produced by fermentation with koji, or Aspergillus oryzae . The koji is mixed with a mass of steamed soybeans and wheat, which is left to rest for 3 days. When enough “fungus” has grown on the dough, it is mixed with salt water and the mixture is put into the barrels. Microbes present in the cellar and barrels continue the fermentation, breaking down the proteins present in the soy and wheat. After fermenting for 6 months to 1 year, the resulting dough, known as moromi, is squeezed into soy sauce.” Shibanuma tells us that his company can produce 300 different “flavors” of soy sauce, depending from the cellar, barrels and fermentation process.The company also produces low-salt, alcohol-free soy sauce for halal use, and ponzu soy sauce without bonito flakes for vegetarians.

“Nowadays you hear about allergies to wheat and other components in the news, but the fermentation process removes the allergens present in soybeans and wheat,” Shibanuma said. The barrels are not rinsed after use; once emptied , moromi is added for the next production.The microbes that live in the barrels don’t just ferment, they also kill other unwanted bacteria, so adding the moromi keeps the barrel’s ecosystem healthier than “cleaning” it after its use.Fermentation continues throughout the year, without artificial temperature control.And it continues even while you are reading this article.

If you want to discover more about this specific soy sauce product, we invite you to visit Shibanuma Soy Sauce directly at their website www.shibanuma.com