Abstract: A process for producing concentrated shoyu which comprises adding and mixing a shoyu koji into the juice separated from a shoyu moromi in the early stage of brewing, used as a brewing water, and then carrying out fermentation and ageing according to the usual method.

Abstract: In a method for producing a fermentation product which comprises inoculating a mold in a substrate and cultivating it, the improvement which comprises adding(A) at least one compound selected from the group consisting of salts of aliphatic carboxylic acids having 1 to 4 carbon atoms, and(B) at least one compound selected from the group consisting of chlorous acid, hypochlorous acid, sulfurous acid, hyposulfurous acid, hydrogensulfurous acid, pyrosulfurous acid, salts of these acids, hydrogen peroxide, bleaching powder, chloramine-B, chloramine-T, halazone and acrylamideat any time ranging from a step of preparing the substrate to the step of cultivation.

Abstract: In a process for producing a solid koji for a fermented food product which comprises inoculating a koji mold in a modified koji substrate and cultivating it at a temperature of about 20.degree. C. to about 40.degree. C. for a time sufficient to produce a solid koji for fermented food products, the improvement wherein at a certain time during a period of about 10 hours to about 20 hours after the inoculation of the koji mold, the cultivation system is subjected to a drying treatment to adjust its water content to about 30.+-.5%.

Abstract: In a process for producing koji for a fermented food product which comprises inoculating a koji mold in a modified koji substrate and cultivating it at a temperature of about 20.degree. C. to about 40.degree. C. for a time sufficient to produce koji for the fermented food product in the presence of a salt of an aliphatic carboxylic acid with up to 4 carbon atoms; the improvement wherein the cultivation is carried out in the presence of at least one added member selected from the group consisting of lactic acid bacteria and yeasts.

Abstract: In a process for producing a fermented liquid food product by fermenting a moromi which comprises a koji for the fermented liquid food product, a moromi substrate and a liquid such as brine, alcohol and water at a temperature of about 10.degree. to about 40.degree. C for a time sufficient to produce the fermented liquid food product; the improvement wherein the fermentation is carried out in the presence of about 0.05 to about 10% by weight, based on the total weight of the koji and moromi substrate, of an added metal salt selected from the group consisting of potassium salts, sodium salts, calcium salts and magnesium salts of aliphatic carboxylic acids containing up to 4 carbon atoms.

Abstract: In a process for producing koji which comprises inoculating a koji mold in a modified koji substrate and cultivating it at a temperature of 20.degree. to 40.degree. C. for a time sufficient to produce koji, the improvement wherein the cultivation is carried out in the presence of 0.05 to 8% by weight, based on the total weight of the unmodified koji substrate, of a sodium or potassium salt of an aliphatic carboxylic acid containing up to 4 carbon atoms. The improved process makes it possible to inhibit bacterial contamination of the cultivation system, and provides good quality koji which exhibits high ratios of nitrogen and sugar utilization in the manufacture of fermented food products such as soy sauce, miso and mirin.