"Japji" was an old cookbook written in 1721. There are 27 types of foods recorded in "Japji"; 10 descriptions of Byeonggwaryu (rice cakes and cookies): Yakgwa, Junggye, Mandugwa, Chaesugwa, Umujeonggwa, Dongajeonggwa, Baekjapyeon, Aengdupyeon, Toranbyeong, and Yeot; and 16 descriptions of Chanpumryu (side dishes): Jinjumyeon, Jeunggyetang, Geumjungtang, Eoreumtang, Changjajjim, Gajijjim, Oejjim, Dubuseon, Dubuneureumi, Geneureumi, Gesanjeok, Hodojaban, Jeonyak, Seokryutang, Sungeojuak, and Yangmandu. There is also a description of Gugija (Chinese wolfberry) liquor. Here, comparative analysis based on culinary science was carried out on the Korean foods recorded in "Japji" as well as the similar foods recorded in "Gyuhapchongseo" (Women's Encyclopedia) written around 1815. Of the 27 types of Korean foods recorded in "Japji", 13 were also found recorded in "Gyuhapchongseo". The time period for "Japji" can be assumed to be 1721 based on the fact that it is written in a cursive handwriting style of Hangeul, that chili was never used as an ingredient, and that the word "Shinchuknyeon (辛丑年)" was transcribed at the beginning of the book. The dating method also included considerations of whether Neureumi was used or not as well as changes in its cooking style.