After some time had passed it was written in the 1697 honsosho (book of herbs) "Honcho shokkan" (mirror of food in our country) that udon noodles were items for cold times and hiyamugi noodles were good for hot times.
時代が過ぎ元禄10年の本草書『本朝食鑑』では、うどんは寒い時期のものであり、ひやむぎは暑い時期に良いとの内容で書かれている。