Food · Fermented seasonings

Saishikomi Soy Sauce (Twice-Brewed)

再仕込み醤油 (Saishikomi shōyu)

Also known as: Twice-Brewed Soy Sauce, Sweet Soy Sauce (Yamaguchi), Kanro Shōyu

Looking for a Japanese supplier of Saishikomi Soy Sauce (Twice-Brewed)? Tell us

At a glance

Category	Food
Japanese labeling name	さいしこみしょうゆ
Common Japanese notations	再仕込み醤油, さいしこみしょうゆ, 甘露醤油
Origin	Fermented twice (soybeans, wheat, salt; existing soy sauce used in place of brine in second fermentation)
Typical functions	Premium dipping soy sauce, Concentrated finishing sauce for sashimi and sushi, Specialty bottled retail SKU
Regulatory status in Japan	Standardized under the JAS standard for soy sauce. Less than 1% of total Japanese soy sauce production. Production concentrated in Yamaguchi (Yanai) and parts of Kyushu.

Saishikomi shōyu (再仕込み醤油) — literally 'twice-brewed soy sauce' — is the most concentrated of the five JAS soy sauce varieties. Instead of mixing koji with brine (saltwater) for the moromi fermentation, saishikomi production uses an already-finished soy sauce in place of the brine. The result is a darker, thicker, sweeter, and more umami-dense sauce, typically reserved as a premium dipping or finishing seasoning. Yanai, in Yamaguchi Prefecture, is the historic center of saishikomi production and gives the variety its alternate name kanro shōyu (甘露醤油, 'sweet-dew soy sauce').

Classification

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

Product applications

Functions

Flavoring

Regulatory tags

Culinary ingredient

Origin

Used in (typical product categories)

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

Premium bottled dipping soy sauce
Sashimi and sushi specialty supply
Export gourmet condiment

What it is

Saishikomi soy sauce is produced by a two-stage fermentation. In the first stage, koji (Aspergillus oryzae on cooked soybeans and roasted wheat) is mixed with brine to form moromi and fermented to produce a finished soy sauce. In the second stage, fresh koji is mixed with the already-finished soy sauce — instead of fresh brine — and fermented again. The two-stage process consumes roughly twice the raw materials and twice the time of standard koikuchi production.

The finished saishikomi shōyu is darker than koikuchi, with a thicker viscosity, higher total nitrogen content, and a more rounded sweetness due to greater accumulation of sugars and amino acids during the two-stage fermentation.

Yanai (Yamaguchi Prefecture) is the historic and modern center of saishikomi production. Yanai-style saishikomi is also marketed as kanro shōyu (甘露醤油), referencing its sweetness. Limited production also exists in Kyushu and other regions.

Typical uses in Japanese products

Saishikomi shōyu is positioned as a premium dipping and finishing sauce. Most commonly used neat for sashimi, sushi, tofu, or grilled fish — applications where its concentrated flavor stands out.

Because of its high cost per volume, saishikomi is rarely used as a general cooking soy sauce. Restaurant chefs use it as a finishing element rather than a base ingredient.

Export markets position saishikomi as a top-tier 'craft soy sauce' product, sold in small-format glass bottles often with the Yanai geographic origin highlighted.

Regulatory classification in Japan

Saishikomi shōyu is one of the five JAS-defined soy sauce varieties under the Japanese Agricultural Standard for soy sauce.

JAS specifies higher total nitrogen content (umami compounds) and higher salt content than koikuchi for saishikomi.

Allergens: soy and wheat must be declared on labels.

Regulatory classification in other markets

EU	Imported as a fermented soy sauce. Higher concentration may affect 3-MCPD and 1,3-DCP profiles; importers should request producer test results.
USA	Imported under FDA standard food procedures. Allergen labeling for soybeans and wheat required.
China	Imported under GACC rules for fermented condiments.
Korea	Imported as a fermented soy sauce; specialty rather than mainstream category.

Example products

Example finished products will be added after verifying producer's two-stage brewing process documentation.

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

Used in similar product applications

Other ingredients commonly used in the same finished-product families.

Sharing similar functions

Ingredients that overlap on functional benefit tags.

From the same origin

Other ingredients that share an origin classification.

FAQ for OEM buyers

Q. What does 'twice-brewed' actually mean for saishikomi soy sauce?

In standard koikuchi production, koji (cultured soybeans and wheat) is mixed with brine (saltwater) to form the moromi mash, which then ferments. In saishikomi production, koji is instead mixed with already-finished soy sauce in place of the brine, and the second-stage moromi ferments again. The process uses roughly twice the raw materials and twice the time, producing a darker, thicker, more concentrated sauce.

Sources · Last reviewed: 2026-04-28

JAS standard for soy sauce — saishikomi production specification

Q. Why is saishikomi sometimes called 'sweet soy sauce'?

The two-stage fermentation accumulates more sugars and amino acids than single-stage koikuchi production. Yanai-style saishikomi (Yamaguchi Prefecture) is marketed under the alternate name kanro shōyu (甘露醤油, 'sweet-dew soy sauce'), reflecting this rounder, sweeter character. The sweetness is intrinsic to the fermentation, not from added sugar.