It was a commentary of the Yoro ritsuryo code (code promulgated in the Yoro period) in which there is a description on a sake brewing method by rice malt that was guessed to be done from the Asuka period to the Nara period.
養老律令の私撰注釈書で、飛鳥時代から奈良時代と推定される米麹による酒造法が記述されている。