A moderate amount of bittern is added to the warm soy milk as a coagulant, and it's stirred with a wooden board called a kai (paddle) (the series of task after the addition of bittern is called "yose," and it's a high point where the workman shows his technique).
この豆乳が冷えないうちに凝固剤としてにがりを適度に加え、櫂と呼ばれる木の板で撹拌する（にがりを打った以降の一連の作業を寄せと呼び、職人の技の見せ所である）。