Uiro

Uiro takes its name from a medicine, not a sweet. In the late 14th century a family descended from Chen Zongjing — an official who had held the post of yuanwailang (員外郎) at the Yuan Chinese court — fled the dynasty's collapse and settled in Japan, first around Hakata and Kyoto and later in Odawara, where they compounded a breath-freshening herbal pill known as uiro or transtōkō (透頂香). How the confection inherited that name is told two ways in the old sources: one account says a steamed sweet resembling the dark medicine in color and shape simply borrowed its name, while another holds it was the palate-cleanser served alongside the pill when the family presented their medicine at court. References to uiro as a confection appear by the early 18th century, and Nagoya makers built the modern trade — Mochibun, founded in 1659, is counted among the oldest, while Aoyagi secured the sole licence to sell uiro aboard the Tōkaidō Shinkansen from its 1964 opening, carrying the Nagoya version to nationwide fame as a souvenir. The medicine itself lives on in the famous kabuki tongue-twister Uiro-uri, a rapid-fire sales patter for the pill.

The first impression is a cool, smooth, very slightly slippery surface that gives way to a dense, springy chew — closer to a firm jelly than to a fluffy cake, with none of mochi's long stretch. The sweetness is restrained and clean, letting the flavoring carry the cake: grassy and faintly bitter in the matcha version, dark and molasses-deep in the kurozato one. It is usually served chilled in neat fingers, where the firm, sliceable body and quiet sweetness make it an unfussy companion to green tea.

Uiro is steamed, not pounded, and that single difference defines its texture. A loose batter of non-glutinous rice flour (joshinko), sugar, and water is poured into a mold; under steam the rice starch absorbs water and gelatinizes, swelling and then setting on cooling into a firm, cohesive, slightly translucent crumb. Because uruchi rice flour is simply steamed rather than hot-pounded the way mochi rice is, no stretchy glutinous network is worked up, so uiro reads as dense and short rather than elastic. The sugar holds water in the set gel, keeping the cake moist and supple and slowing it from drying or hardening as quickly as a leaner steamed cake would.