A method for aging a fermented product includes the steps of: (a) cooling the fermented product in a container; (b) introducing ozone in the cooled fermented product for oxidation; and (c) applying an ultrasonic vibration to the container to vibrate and heat the fermented product in step (b) for oxidizing the fermented product. An aging device for a fermented product includes: an aging tank for containing the fermented product, the aging tank having an inlet and an outlet for the fermented product; an ozone supplying unit having an inlet pipe and an outlet pipe which are connected to the aging tank; a cooling unit mounted to the aging tank; an ultrasonic vibration unit mounted to the aging tank; and a thermometer mounted on the aging tank to detect the temperature of the fermented product. A method for preparing a distilled liquor includes the steps of (a') distilling a fermented precursor; (b') chilling the distilled fermented precursor; and (c') aging the chilled fermented precursor by the aging method described above.
