Additionally, there is a theory that states that there were noodles called 'kirimugi' that were made by kneading wheat flour and water, cut into strips, then boiled and eaten, and a distinction was made between those eaten warm as 'udon' and those eaten chilled as 'hiyamugi.'
他には、小麦粉を水で練ったものを細く切り、茹でて食べるものを「切り麦」と呼んでいたが、これを暖めて食べるものを「饂飩」、冷やして食べるものを「冷麦」と分けたからという説がある。