About 83% of all soy sauce products consumed
in Japan in 2002 was of this type.
Japanese style fermented soy sauce is prepared by digesting
mold-cultured soybeans and wheat, called koji in Japan,
at different ratios, usually about 50:50, in the presence of
about 17% sodium chloride and concurrently fermenting the
mash with lactobacilli and yeasts. After 6–8 months the
well-aged mash is pressed and the liquid part obtained is
pasteurized to make the final product.
Five varieties of soy sauce are available in Japan: (i)
koikuchi (a dark-colored common soy sauce produced using
soybeans and wheat in almost the same quantities as the raw