Abstract: The present invention relates to a process for producing a soy sauce koji having a reduced Busho-shu which is one of the unpleasant smells of soy sauce, and a soy sauce koji having a reduced Busho-shu obtained by this production process. Specifically, the process for producing a soy sauce koji is characterized by using a combination of a koji mold having a high isobutyric acid productivity and another koji mold having a low isobutyric acid productivity. The present invention also relates to a process for producing a soy sauce having a reduced Busho-shu and a soy sauce obtained by this production process.

Abstract: According to the present invention, there is reliably provided a soy sauce having desired ethanol and lactic acid concentrations and a mellow flavor. A method of brewing soy sauce which comprises mixing soy sauce koji into a salt water to prepare a soy sauce moromi mash, adding pre-cultured soy sauce lactic acid bacteria and soy sauce yeast to the moromi mash, performing fermentation and aging of the moromi mash after adding by ordinary techniques, wherein the soy sauce yeast is added to the soy sauce moromi mash within 10 days after mixing such that the cell count of the soy sauce yeast is 10 to 100 fold greater than that of wild yeast already existing in the moromi mash and is 2×105 or less cells/g moromi mash to the soy sauce moromi mash, so that the desired soy sauce is obtained.