Mochi-tsuki, or the act of pounding rice to make mochi (rice cakes), is an important traditional event in preparation for the New Year in Japan. It’s usually performed at the end of the year, from between December 25th to December 28th.
Making mochi is pretty simple. A special type of sticky rice that’s been soaked in water overnight and steamed is placed in an usu (a large bowl made of wood or stone). A heavy, hammer-like implement is used to pound the rice into a paste. The implement is heavy, so when a family makes mochi together, the father usually does the pounding, with the mother regularly shifting the rice in the usu (with her hands moistened to prevent the mochi from sticking), this ensures evenness. The mother then shapes the pounded rice into small portions with the help of the children.
After the mochi are completed, some are set aside as divine offerings. The decorative kagami mochi – two flat, round mochi placed one on top of the other, with the lower mochi being slightly larger – represents the seat of the New Year deities. Even at room temperature, the mochi will keep for a fairly long time.
The mochi start being eaten at the New Year, with the cakes being one of the principal components of the beloved New Year’s soup ozoni.
Modernisation has seriously weakened the mochi-tsuki tradition, however. Although some farming households still pound their own mochi, most urban residents usually order mochi from specialty shops or buy machine-made, plastic-wrapped rice cakes from the supermarket.