Soy Saucealso: 醬油 · 간장 · nước tương · kecap

Origin

Originated in China around 200 BCE, spread to Japan by the 7th century, to Korea by the same period. Each tradition diverged: the Japanese kicked koji into a much bigger role; the Chinese fermented longer for darker, richer profiles; the Korean version (jang) became thicker and more strongly fermented.

What it tastes like

Salty and umami; fermentation depth varies. Chinese light soy is brisk and salt-forward; Chinese dark soy is sweet and molasses-like; Japanese koikuchi is balanced; tamari is wheat-free and richer; Korean joseon ganjang is the most pungent.

How it's used

Universal. The cuisine and the recipe dictate the type — substituting is not a 1-to-1 swap.

Buying

Light soy: Pearl River Bridge or Lee Kum Kee. Dark soy: same brands, look for 'dark' or 'lao chou'. Japanese: Kikkoman is acceptable, Yamasa is better, Yamaroku Kiku Bisi is sublime. Korean: Sempio.

Substitutes

Tamari (gluten-free), coconut aminos (lower-sodium, sweeter). Avoid 'low-sodium' versions for cooking — they have less umami too.

Storage

Pantry until opened, refrigerated after for best flavour. Indefinitely stable.