What is Wakashi in Japanese Katana terminology?

"Wakashi" (沸かし) refers to the process of heating steel until it melts and becomes soft. This is a crucial step in the process of making a Japanese sword. The steel, known as Tamahagane, is heated in a furnace until it reaches a state where it is malleable and can be shaped. This process is carefully controlled by the swordsmith to ensure the steel does not overheat and lose its desirable properties. The heating process also helps to remove impurities from the steel, contributing to the quality and strength of the final sword.