Shōgatsu (New Year’s) is the most important holiday on the Japanese calendar, and the dishes associated with it are laden with symbolic meaning. While the colorful foods of osechi, packed attractively in jūbako (stacking bento boxes), are the flamboyant attention-catchers of the New Year’s feast, the quiet star of the show and the food with the most historic and spiritual significance is mochi.
Mochi is made from mochi-mai, a type of rice known as “glutinous” or “sweet” in English. This short-grain rice is much stickier than the medium-grain uruchi-mai rice that’s standard in Japanese cuisine.
Traditionally, mochi-mai was considered to be more desirable than uruchi-mai, and the pounded cake form, mochi, was a highly prized luxury food only affordable to the ruling classes. That’s because mochi-mai yields are low, and quite a lot of it is needed to make mochi cakes.
In a sense, mochi is a concentrated version of the food that is revered above all others in Japan: rice.
There are written accounts from the Nara Period (710-794) of mochi as a sacred food. One tale recounts the story of a man who tried to use a mochi cake as a target for archery practice. When he hit the mochi, it magically turned into a white swan and flew away, and shortly thereafter all the rice paddies in the area dried up, causing people to starve. The message is that rice, and the products made from it, should never be wasted.
The first recorded accounts of mochi being used as part of the New Year’s festivities comes from the Heian period (794-1185). To the nobles of the Imperial court, the long strands of fresh mochi were thought to symbolize long life, and the hardness of dried mochi was thought to make one’s teeth tougher and more durable — good teeth being critical to one’s health and well-being. There’s even an account of mochi at New Year’s in “The Tale of Genji,” the oldest novel in the Japanese language.
The most important symbolic New Year’s mochi is the kagami-mochi, a decorated stack of two rounded mochi cakes that is put on display. The name, which means “mirror mochi,” comes from its shape, which is supposed to be like the round bronze mirrors used by the aristocracy for centuries. (Another theory holds that it looks like a human heart).
The kagami-mochi is usually put out for display on Dec. 28, because the number eight is considered to be an auspicious number in Japanese numerology, and never on the 29th, because the number nine can be read as ku (“suffering”). Some people choose to put out their kagami-mochi on the Taian (“big luck”) day closest to the end of the year.
While the kagami-mochi is mainly a display piece, mochi is also the only source of starch allowed during the first three to seven days of the New Year’s festivities. (Nowadays a lot of people break with this tradition and start eating regular rice as early as Jan. 2, which is a bit of a shame.)
Besides all the symbolic significance of eating mochi, this traditionally gave a break to the cook of the household too, since she (and it was usually a she) didn’t have to prepare and cook the rice, once a significant chore.
To prepare the mochi to be consumed during the New Year period, steamed mochi-mai was pounded into mochi on the Dec. 29; the vigorous pounding action was supposed to beat ku (suffering) into submission. The pounded mochi was then spread out onto trays to dry out and cut into squares (kiri-mochi) in eastern and northern parts of Japan, or formed into small round cakes (maru-mochi) elsewhere; these dried-out cakes would last for several days.
Pounding mochi in a hollowed-out wooden log barrel with a big hammer used to be a back-breaking chore. It’s still done mostly as a symbolic gesture in many parts of the country, but most people who bother to make their own mochi these days use an electric mochi-pounding machine.
Most mochi consumed at New Year’s is prepared as ozōni, a soup with mochi cakes in it. Every region of the country, and possibly every family, has its own recipe for ozōni. For example, in Kyoto it is made with a white miso-soup base using round maru-mochi. In Hakata in Kyushu, pieces of buri (amberjack), taro root, shiitake mushrooms and so on are cooked in a clear soup, eaten with chestnut-wood chopsticks for good luck. And on the coastal areas of Hokkaido, ozōni is often topped with an extravagant variety of fresh local seafood, such as crabmeat and ikura (marinated salmon caviar).
Another way of enjoying dried mochi cakes is to cook them on a special wire grill called a mochi-ami until puffy and lightly browned, then to dunk them in a sauce or coating of your choice. My favorite is the classic isobe-mochi, square kiri-mochi coated in soy sauce and wrapped with a piece of nori seaweed. This kind of mochi can be enjoyed at any time of the year these days, with the easy availability of ready-made dried mochi cakes. And even though the sight of a mochi cake puffing up on a mochi-ami is very atmospheric, cooking the mochi in a toaster oven works just as well.
A word of warning before you dive into your mochi. Every year, several people — most of whom are elderly — are rushed to the emergency room after choking on mochi. Mochi is actually the leading edible cause of death by choking, far more than foods that have been banned as choking hazards in some countries, such as konyaku jellies. Make sure to bite off small bits from the sticky mass and to chew well before swallowing. Keep in mind that the pounded mochi favored in Japan is a lot stickier than mochi made from rice powder, which is the norm in other Asian countries such as China.
There’s one final mochi ritual to finish out the New Year: the day of kagami-biraki, or “opening of the mirror,” which usually occurs on Jan. 11. The dried out kagami-mochi cakes are broken up with a hammer, never cut with a knife — cutting a sacred offering is considered to bring very bad fortune. The pieces are often cooked in sweet azuki bean-paste soup as shiruko, but when I was growing up my mother would always break up the pieces further, leave them out to dry out completely and then deep-fry them to turn them into kaki-mochi, or crispy rice crackers. A perfect start to a brand new year.