Food · Seasonings

Black Vinegar (Kurozu)

黒酢 (Kurozu)

Also known as: Kurozu

At a glance

CategoryFood
INCI nameNot applicable (food use)
Japanese labeling nameNot applicable (food use)
Common Japanese notations黒酢, クロズ
OriginFermented (extended-aging rice vinegar)
Typical functionsFood seasoning, Functional food ingredient
Regulatory status in JapanFood regulated under the Food Sanitation Act. Some kurozu products are notified under the Foods with Function Claims system where specific claims have been submitted.

Kurozu — black vinegar — is a traditional Japanese rice vinegar produced by extended fermentation and aging, typically in earthenware pots over a period of many months to years. The extended aging produces its characteristic dark color and depth of flavor. The category is particularly associated with Kagoshima prefecture, where producers in the region of Kirishima have been making kurozu for centuries using regionally-specific production methods.

Classification

Tags below link to other ingredients sharing the same attribute, so you can pivot from one ingredient to its peers.

Used in (typical product categories)

Finished-product categories that commonly include this ingredient in Japanese-market formulations.

  • Cooking vinegar
  • Beverage base (diluted kurozu drinks)
  • Supplement ingredient

What it is

Kurozu is produced by fermenting brown rice with koji and then allowing extended outdoor aging in open-topped ceramic pots. The aging duration varies by producer (typically six months to several years). Amino acid content and color depth develop during the extended aging.

Regional branding around specific Kagoshima production areas is common; cosmetic or supplement ingredient labels use generic "black vinegar" or "kurozu" terminology, with specific regional producer names handled as product-level provenance.

Typical uses in Japanese products

In cooking, kurozu is used as a finishing vinegar, in dressings, and in sauces. Its depth of flavor makes it more similar in use to aged balsamic than to plain rice vinegar.

In health-positioned beverages, kurozu is often diluted with water or juice and consumed for its amino acid content.

Some kurozu products and extracts are notified under the Foods with Function Claims system; specific notifications should be verified in the Consumer Affairs Agency database.

Regulatory classification in Japan

Food regulation under Food Sanitation Act. JAS standards apply for rice vinegar classification. Functional food positioning requires notification under the FFC system for any specific claim.

Regulatory classification in other markets

EUFood vinegar permitted. Functional claims require separate review.
USAFood and supplement use established.
ChinaChinese black vinegars are a related but distinct category with different production methods.
KoreaFood use established.

Example products

Example finished products will be added after verification. Regional kurozu brands with established production heritage are handled as descriptive production-region notes.

All brand names and product names referenced anywhere on this site are the property of their respective owners. Example entries are provided for informational purposes only and do not imply endorsement.

Related ingredients

References

  1. MAFF JAS standards — rice vinegar

Last updated: 2026-04-22. Ingredient entries are reviewed at least annually against current regulatory listings.

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