Japan — kome-su (rice vinegar) has been produced in Japan since the Nara period (8th century). The Kyoto vinegar-making tradition (Iio Jozo, est. 1893) uses traditional wooden barrel fermentation. Kurozu's production tradition in Fukuyama (Kagoshima) dates to the late Edo period, when local rice farmers developed the earthenware-jar brewing method that is still used today.
Japanese vinegar (su, 酢) spans a wider range of flavour, acidity, and colour than any single other cuisine's vinegar tradition — from the mild, clean kome-su (米酢, rice vinegar, 4–5% acidity, pale golden) to the deep, mellow kurozu (黒酢, black vinegar, aged for 3+ years in earthenware pots until developing an amber-black colour and a complex, almost balsamic character). The primary types: kome-su (rice vinegar) — the standard sushi rice seasoning and general-purpose Japanese vinegar; kurozu (black vinegar, from Kagoshima) — aged, complex, used as a condiment and health food; sanbaizu (三杯酢, three-cup vinegar) — rice vinegar + soy + mirin as a composite dressing; awasezu (合わせ酢, sushi vinegar) — rice vinegar + salt + sugar for sushi rice.
Kome-su's flavour is gentle and clean — a mild acidity with a faint sweetness and a clean, neutral character that adds brightness without asserting a strong wine or grain flavour. This is precisely why it works in sushi rice: the vinegar elevates the rice's flavour without competing with the fish. Kurozu's aged character is completely different — deep, complex, slightly caramelised, with hints of umami from the long fermentation; a few drops on stir-fried bitter greens or cold tofu transforms the preparation with a quiet, complex acidity that bears no resemblance to ordinary vinegar.
Kome-su (rice vinegar): the standard for sushi rice seasoning, ponzu preparation, nimono pickles, and salad dressings. Its low acidity (4–5%) and gentle, clean flavour are specifically calibrated for Japanese preparations where strong vinegar would overwhelm. The sushi rice awasezu ratio: rice vinegar 100ml + salt 15g + sugar 30g per 550g cooked rice. For sunomono (酢の物, vinegared salads): kome-su + mirin + soy sauce in a 3:1:1 ratio is the standard sanbaizu dressing. Kurozu application: best used as a direct condiment (a few drops on stir-fried vegetables) or in a reduction-based sauce; the complex aged character is too delicate to cook for long periods.
Kurozu from the Fukuyama area of Kagoshima (桷志田, Kakuida brand, aged 3–5 years) has a specific smooth, complex, deep flavour that Japanese health-food culture prizes highly — it contains more amino acids than shorter-aged vinegars (from the extended fermentation) and has a flavour profile that genuinely parallels artisan balsamic. A dressing of kurozu + ginger + sesame + soy produces a vinaigrette of extraordinary depth for cold tofu, blanched broccoli, or sashimi accompaniments. Homemade awasezu (sushi vinegar): warm the rice vinegar gently to dissolve the sugar, never boil — boiling drives off the volatile acids, producing a flat vinegar.
Substituting Western white wine vinegar for kome-su — its higher acidity (5–7%) and sharper, wine-derived character produce an aggressively acidic result where kome-su's gentleness is required. Over-heating kurozu — the complex volatile compounds that make black vinegar distinctive are heat-sensitive; use at room temperature or in low-heat applications.
Washoku — Elizabeth Andoh; Japanese Cooking: A Simple Art — Shizuo Tsuji