Southern Japanese Iron Kettles Southern iron kettles are crafted using traditional manual casting techniques—such as the lost-wax method—in a complex process involving over 80 distinct steps. Adhering to the principle of "one mold, one kettle," the mold is shattered immediately after each piece is cast, thereby guaranteeing the absolute uniqueness of every finished work. A craftsman must undergo a rigorous apprenticeship of more than 15 years before being deemed capable of working independently; should one aspire to the mastery required to engrave one's signature onto the body of a kettle, a lifetime of dedication—spanning some 30 to 40 years—is required.