THERE are countless New Year traditions, but as I, actor Daniel S. Janik (aka author Raymond Gaynor) and my partner, actress Sakura Kai (aka author Setsuko Tsuchiya) represent a melding of Western and Asian cultures, one of our favorite New Year traditions is making mochi.

The “recipe” is quite simple: Make some rice, specifically mochigome (糯米), a short-grain glutinous rice. In general, the better the “quality” of the rice, the better the mochi. But that’s only half of what make...