The invention discloses a round koji making process utilizing soybean and flour as raw materials. The process comprises the following steps of 1) soaking the soybean; 2)
steaming; 3) cooling; 4); inoculating and mixing the flour, namely inoculating koji extract into the cooled ripe soybean, adding the flour and mixing the raw materials to obtain a mixture; 5) feeding, namely inputting the mixture into a koji chamber of a round koji maker; 6), cultivating
yeast for making hard liquor, namely cultivating the mixture in the koji chamber of the round koji maker, specifically including the steps of earlier-stage cultivation, primary koji turning after the earlier-stage cultivation, middle-stage cultivation, secondary koji turning after the middle-stage cultivation, later-stage cultivation,
tertiary koji turning after the later-stage cultivation, and terminal-stage cultivation in sequence; 7) discharging koji, namely after cultivation of the
yeast for making the hard liquor is finished, pumping the
yeast for making hard liquor, which is mixed with
saline, into an airing tank. The process can be used for solving the problem of hardening during a cultivation process of the yeast for making the hard liquor, improving the quality of the yeast for making the hard liquor and lowering the labor cost; furthermore, the yeast for making the hard liquor, prepared by the process, has the characteristics of less quantity of infectious microbes and high
enzyme activity.