PROBLEM TO BE SOLVED: To provide a method for producing a salt-free Miso type food material which has a strong taste of body with fullness and richness. SOLUTION: The method includes the following steps: A liquid Koji is prepared by culturing a Koji mould in a predetermined amount of a liquid culture medium (or the supernatant thereof) of a lactic acid bacterium. The liquid Koji thus obtained is added to a food material and Koji-making is conducted in a closed Koji-making machine while continuously or intermittently supplying sterilized air thereinto. Next, the obtained Koji is mixed with a liquid culture medium (or the supernatant thereof) of a lactic acid bacterium and, if necessary, an additional food material is further blended. The obtained mixture is processed directly or in the form of past into a Moromi either as such or as a paste. Then, this Moromi is hydrolyzed in the absence of sodium chloride. COPYRIGHT: (C)2008,JPO&INPIT