Sunomono

Sunomono — literally 'vinegared things' — is a category rather than a single recipe, covering any dish dressed in seasoned vinegar (sunomono and the closely related aemono together make up Japan's repertoire of dressed small dishes). Vinegar (su) has been produced in Japan since rice-vinegar brewing techniques arrived from the Asian mainland in antiquity, and acidulated dishes are long documented in Japanese cooking; no single inventor or birthplace can be attributed to so basic a preparation. The standard dressings are codified by name: nibaizu (vinegar and soy sauce), sanbaizu (vinegar, soy sauce, and mirin or sugar, the everyday choice for cucumber sunomono), and tosazu (sanbaizu enriched with bonito dashi). Sunomono sits in the formal meal as the su-no-mono course, a vinegared dish meant to reset the palate.

Chilled and bright, sunomono hits sour first, then a softer sweetness and a savory undertone from the soy. The cucumber should snap crisply between the teeth — a clean, watery crunch — while the wakame is silky and slippery and any octopus is firm and faintly chewy. The contrast of crisp and slick under the cool vinegar is the whole appeal. A well-made bowl is lightly dressed and not swimming in liquid; if the cucumber wasn't salted and pressed first, it goes limp and floods the dish, dulling the vinegar.

The texture trick is osmosis: salting the sliced cucumber draws water out of the cells through their membranes, so by the time it is wrung out the cucumber has shed the liquid that would otherwise leach into the dressing and turn the dish thin and watery within minutes. Pressing it dry also concentrates the cucumber's own crispness and lets it take on the dressing instead of diluting it. The dressing itself is a balance of acid, salt, and sweetness — vinegar for tartness, soy sauce for salt and savory depth, mirin or sugar to round the sourness so it reads refreshing rather than harsh; tosazu adds dried-bonito dashi, whose inosinate brings umami to the sour base. Dried wakame is rehydrated separately and squeezed so it, too, does not water down the bowl, and seafood is added cooked and cooled so it stays firm in the cold vinegar.