This step is officially called "jokyo" ("kyo" is composed of a left radical "食" (eating or food) and a right radical "強" (strong), or "mushi" (steaming) by the language of toji.
この工程を正式には蒸きょう（じょうきょう：「きょう」は「食へんに強」）、もしくは杜氏蔵人言葉で蒸しという。