Japanese Shiro Shoyu White Soy Sauce and Saishikomi Double-Brewed Soy

Japan (Aichi Prefecture for shiro shoyu; San'in region for saishikomi; Hyogo for usukuchi; Chubu for tamari)

Japanese soy sauce encompasses far more than the standard koikuchi dark variety. Shiro shoyu (white soy sauce), produced predominantly in Aichi Prefecture, is brewed with a high ratio of wheat to soybean—sometimes nearly all wheat—resulting in a pale golden liquid with delicate sweetness and minimal colour impact. This makes it indispensable in dishes where visual clarity matters: chawanmushi, clear soups, and light-coloured nimono where dark soy would muddy the presentation. At the opposite pole, saishikomi (twice-brewed or re-brewed soy sauce) undergoes fermentation using existing soy sauce as the liquid medium rather than brine, producing an intensely flavoured, syrup-thick condiment of profound depth. Also called kanro shoyu (sweet soy), it is most identified with the San'in region (Yamaguchi, Shimane) where it serves as a sashimi condiment rather than a cooking ingredient. Between these extremes lie usukuchi (light soy sauce) from Hyogo—pale but saltier than standard—and tamari from the Chubu region, which is the traditional by-product of miso pressing and contains little or no wheat, making it gluten-free and intensely savoury with a viscous consistency. Understanding these five principal varieties—koikuchi, usukuchi, tamari, shiro, and saishikomi—allows the chef to match the condiment to application with precision.

Shiro: delicate, sweet, barely savoury; Saishikomi: deeply complex, syrupy, fermented; Usukuchi: saline, sharp; Tamari: viscous, rich, umami-forward; Koikuchi: balanced benchmark