Mochi (餅) is made from mochigome (糯米 — glutinous rice), a variety of rice with almost no amylose starch and a very high amylopectin content — the molecular composition that produces its extraordinary elasticity when cooked and pounded. Mochi appears in Japanese records from at least the eighth century CE. Its preparation for New Year (oshōgatsu) is among the oldest continuous food rituals in Japan — the mochitsuki (mochi-pounding ceremony), in which two people alternate strikes with a heavy wooden mallet on cooked glutinous rice in a stone mortar, was observed in imperial courts and village squares simultaneously and still is.
Mochi's character comes from the transformation of starch: mochigome's amylopectin-dominant starch, when fully cooked and then mechanically worked (pounded or kneaded), produces a network of interlocked starch chains that is simultaneously elastic (it stretches without breaking), cohesive (it holds its shape), and sticky (it adheres to itself and to the filling it encloses). This network is unlike any other food texture in the world. No Western ingredient produces it. Gelatine produces a set; cornflour produces a thickened liquid; agar produces a firm gel. None are elastic in the way of mochi.
1. Mochigome must be soaked overnight before steaming — minimum 8 hours, which allows the grains to fully hydrate before the starch gelatinises 2. The mochi must be worked while hot — as it cools below 50°C, the starch network begins to set irreversibly. Re-warming is possible but produces a coarser texture. 3. Dusting with katakuriko (片栗粉 — potato starch) or cornstarch prevents sticking during shaping — this dusting is the only thing standing between mochi and an unusable, adhesive mass 4. The filling must be cold (refrigerator temperature) when the mochi skin is applied — warm filling sticks to the starch dusting and tears the skin Sensory tests: - **The stretch test:** Correctly made mochi stretched between two fingers produces a slow, smooth, continuous elongation — not tearing, not snapping, but a controlled elastic extension. If it tears immediately, the mochi was over-worked or is too cold. If it has no elasticity (flows rather than stretches), it is too warm. - **The thickness test (daifuku skin):** Hold a shaped daifuku up to a light. The skin should be slightly translucent at its thinnest point — around 4–5mm. An opaque skin is too thick; a skin through which the filling colour is clearly visible is too thin. - **Taste at temperature:** Mochi at room temperature should feel cool on the tongue — the starch network absorbs heat from the mouth slightly before the flavour arrives. This thermal delay is characteristic and desirable.
Japanese Confectionery Deep: Wagashi, An, Mochi & the Seasonal Sweet Tradition