Rice Vinegar (Komezu) (米酢)
Vinegar brewed from sake or sake lees - the gentle acid behind sushi rice and suzuke pickles.
| How it is made | Alcohol (from sake, or sake kasu) converted to acetic acid by acetic acid bacteria - a second fermentation after brewing |
|---|---|
| Types | Komezu (from sake), kasuzu (from sake lees, aged and amber, a speciality of Fukuoka's traditional makers), and blended grain vinegars |
| Character | Milder and rounder than distilled white vinegar - which is why sushi rice uses it |
Rice vinegar is fermentation squared: rice is brewed into sake, and sake is fermented again into vinegar. The kasu route goes further and ages the lees themselves into a dark, mellow vinegar prized for sushi in parts of Kyushu.
Buying note: labels distinguish pure rice vinegar (jun komezu, only rice) from grain vinegar (kokumotsu-su, blended cereals) and from synthetic vinegar. For sushi rice and dressings the pure rice type is the reference; acidity percentages are printed on the label and vary by product.
See also
SuzukeRelated page in this guide.Sake kasu
Related page in this guide.
Sources: Ministry of Agriculture, Forestry and Fisheries (MAFF), 'Traditional Foods in Japan'; JAS soy sauce standards; Umami Information Center; Kikkoman official information; Wikipedia (CC BY-SA 4.0). Checked 6 November 2026.