Japanese Mochi Production Kirimochi and Kagami Mochi New Year Traditions

Ingredients

• For the mochi
• 500 g mochigome (glutinous rice / sweet rice), labelled 'glutinous rice' or 'sweet rice'; uruchi-mai cannot be substituted
• as needed water, for soaking and for wetting the mochi during pounding
• as needed katakuriko (potato starch) or cornstarch, for dusting work surface and hands
• For serving (select one or more)
• as needed kinako (roasted soybean flour), for dusting finished mochi
• as needed soy sauce
• as needed toasted nori, torn into sheets for wrapping
• as needed sweet red bean paste (anko)
• For kagami mochi (optional)
• 1 daidai orange, placed on top of the stacked rounds as New Year decoration

Method

1. 1
   Wash the mochigome in several changes of cold water until the water runs clear. Cover with fresh cold water and soak for several hours or overnight. Drain thoroughly before steaming. The grains should feel swollen and opaque throughout — no chalky core at the centre when one is split.
2. 2
   Steam the soaked mochigome over vigorously boiling water in a cloth-lined steamer until fully gelatinised — the grains must be completely translucent and cohesive, with no residual raw starch at the centre. Press a grain between two fingers: it should offer no resistance and flatten without crumbling. Understeamed mochigome will not pound to a smooth mass.
3. 3
   Transfer the steamed rice immediately to a warmed usu (mortar) or, for home production, a heavy bowl or the bowl of a stand mixer fitted with a dough hook. Begin pounding or kneading at once. This step decides the dish: mochi must be worked continuously while hot — as temperature falls below 60°C the amylopectin starch retrogrades, and the mochi becomes stiff and crumbly rather than elastic. Wet the mochi and the kine (mallet) or hook frequently with water to prevent adhesion and to maintain temperature and extensibility. Pound and fold until no individual grains remain and the mass is completely smooth and uniform — a single, glossy, extensible body.
4. 4
   Test the mochi by pulling a small piece between both hands: properly pounded mochi stretches to a thin membrane without tearing. If the surface tears or the mass crumbles, continue pounding, adding water as needed, until the stretch test is passed.
5. 5
   Dust the work surface and hands generously with katakuriko or cornstarch. Turn the mochi out onto the dusted surface. For kirimochi, press the mass into a flat slab of even thickness and allow to cool and firm. Cut into square or rectangular portions with a sharp knife. For kagami mochi, shape the warm mochi into two round cakes — one larger, one smaller — by hand, using dusted palms. Stack smaller on larger on a stand; place the daidai on top. The exterior of shaped mochi should be smooth and taut, showing no surface tears.
6. 6
   To toast kirimochi: score the surface of each piece with a sharp knife before placing under a grill or in a dry pan over medium heat. The scoring allows internal steam to escape and prevents explosive cracking. Toast with patience at medium heat until the exterior is golden and the piece has visibly puffed; the interior should be soft and yielding when pressed lightly. High heat burns the surface before the interior softens.
7. 7
   Serve fresh-pounded mochi immediately with kinako, soy sauce and nori, or anko. Fresh mochi should be consumed within hours of production; its softness, warmth, and rice fragrance are the measure of the idealized form. Commercial kirimochi is shelf-stable and a convenient year-round alternative.