Ozoni: the New Year soup no two families make alike

Ask people in Japan what ozoni (お雑煮) should look like and you'll get a confident answer. Ask someone from the other end of the country and you'll get a completely different answer, delivered with exactly the same confidence. I think that's the loveliest thing about this soup: it is one of the most widely shared New Year traditions in Japan, and almost nobody agrees on what it is.

The one constant is mochi, rice cakes made from glutinous rice that has been steamed and pounded into a smooth, stretchy dough. Everything around the mochi, from the broth to the shape of the cake to what floats beside it, changes with the region and, very often, with the family.

A soup for the first morning of the year

The New Year holiday, shogatsu (正月), is the biggest family moment of the Japanese calendar, and much of it revolves around food. Many households prepare osechi (おせち), New Year dishes packed into stacked lacquer boxes, each item carrying a wish: black beans for health and hard work, herring roe for a family that grows, golden sweet chestnuts for prosperity. Osechi is traditionally made ahead, often explained as a way to let the cook rest over the holiday, and much of it is eaten at room temperature.

Ozoni is the hot counterpart, simmered fresh and eaten in the first days of January, above all on the morning of New Year's Day. The name is modest. Zoni (雑煮) means roughly "a simmered mix", and the polite o- in front hints at the affection it carries. If toshikoshi soba sees the old year out on New Year's Eve, ozoni is the bowl that welcomes the new one in.

Mochi itself is woven into the season. Pounding it at the end of the year, mochitsuki (餅つき), is an old tradition, though plenty of families now simply buy it, and a stacked rice-cake ornament called kagami mochi (鏡餅) sits in many homes through early January.

East and west: square or round, clear or miso

The great divide runs roughly between the Kanto region around Tokyo and the Kansai region around Kyoto and Osaka.

In Kanto, the classic ozoni has a clear broth: a light dashi seasoned with soy sauce and salt. The mochi is square, kaku mochi (角餅), cut from a flat slab and grilled until it puffs up and freckles with brown spots. Into the bowl go a few pieces of chicken, a leafy green such as komatsuna (小松菜), a slice or two of pink-and-white fish cake, and sometimes a sprig of mitsuba (三つ葉), a fresh-tasting Japanese herb. It is tidy, savoury and bright.

In Kyoto, ozoni is a different creature. The broth is made with shiro miso (白味噌), the pale, sweet white miso of the region, which turns it creamy and mellow (there's more on that style in our guide to miso). The mochi is round, maru mochi (丸餅), and it is boiled rather than grilled, so it turns soft and almost molten. Root vegetables such as daikon and taro are often cut into rounds too. Round shapes are often said to stand for harmony, a wish for a year without sharp corners.

Broadly, square mochi dominates in the east and round mochi in the west, with the boundary usually placed somewhere in central Japan. One common explanation for the eastern squares is practical: cutting a big slab into pieces is quicker than shaping each cake by hand. Like most explanations for food customs, take it as plausible rather than proven.

Kagawa's sweet surprise

Then there is Kagawa, on the island of Shikoku, a prefecture better known to travellers for its udon. Here the white miso broth holds an-mochi (あん餅): round mochi with a filling of anko (あんこ), sweet red bean paste.

On paper it sounds as if a dessert has fallen into the soup. In the bowl, the salty, savoury miso and the sweet bean paste meet somewhere in between, a little like salted caramel, and the combination has its loyal defenders. I've never found a single agreed explanation for how the custom began, and honestly I'm not sure it needs one.

These three are only the best-known landmarks. Across Japan you'll find ozoni with seafood, with local vegetables, with mochi grilled or boiled, in broths clear, white or somewhere in between. Within a single town, two neighbouring families can make it quite differently. When two people from different regions set up a home together, deciding whose ozoni appears on the first morning of the year can be a small but very real negotiation.

How to eat it (and a gentle word about mochi)

If you're lucky enough to be offered ozoni at New Year, eat it the way you would any Japanese soup: lift the bowl, sip the broth straight from it, and use chopsticks for the mochi and vegetables. Grilled square mochi holds its shape and has a slightly crisp skin; boiled round mochi is softer and stretches dramatically when you pull at it.

That stretch is part of the pleasure, and also the reason for a gentle reminder. Mochi is soft, sticky and dense, and every winter Japanese news and public health messages remind people to take care with it, especially older relatives and small children. Cut it into small pieces, take small bites, chew thoroughly, and keep tea or water within reach. Nobody wants a New Year story that starts with a rice cake.

If you'd like to try a simple Kanto-style version at home, it needs very little: a good clear dashi seasoned lightly with soy and salt, a few pieces of chicken simmered in it, some greens, and square mochi toasted under the grill until puffed. Put the mochi in the bowl, ladle the hot broth over it, and finish with a few leaves of herb or a thin curl of yuzu peel.

Ozoni is mostly home food, so travellers are most likely to meet it at a New Year meal in a ryokan or hotel rather than at a noodle counter. It's worth seeking out, because it tells you more about where someone comes from than almost any other bowl in Japan.

I think that's the real point of it. A soup that tastes different in every house ends up tasting, to each person who grew up with it, exactly like home on the first morning of the year.