Horenso — Japanese Spinach Traditions
Japan-wide — horenso cultivation in all prefectures, peak quality in winter
Horenso (Japanese spinach, Spinacia oleracea — a winter-harvested variety) is one of Japan's most fundamental leaf vegetables, appearing in virtually every category of Japanese cooking. Unlike Western spinach varieties that are often wilted or sautéed, Japanese cooking has three primary preparations: ohitashi (blanched, squeezed, and dressed with dashi-soy sauce — the quintessential side dish); gomaae (blanched and dressed with sweet sesame sauce); and spinach as ingredient in tamagoyaki, miso soup, and nimono. The key technique is the thorough blanching followed by immediate cold-water shocking to preserve the vivid green colour, followed by squeezing out all water before seasoning (un-squeezed spinach dilutes sauces and creates a watery dish). Winter horenso (fuyu horenso), grown under snow or cold temperatures, is significantly sweeter than summer spinach due to the cold-weather accumulation of natural sugars as an antifreeze mechanism.