Soy sauce
Not salty water but a fermented seasoning. Swapping the type changes the dish, and when you add it decides whether the aroma survives.
The types are not interchangeable
- Regular brewed (Korean jin-ganjang) β deep aroma with some sweetness. Braises, stir-fries, marinades. Bulgogi, Teriyaki Chicken.
- Korean guk-ganjang (soup soy) β saltier and paler. For seasoning a broth without darkening it. Miyeokguk, Kongnamul Guk.
- Chinese dark soy β molasses added, very dark, less salty. Used for colour. Char Siu.
- Tamari β Japanese, made without wheat. Gluten-free and deeply savoury.
Substituting soup soy for regular soy makes the same volume much saltier. Check the type before you adjust the amount.
It is an umami ingredient
Soy sauce is rich in glutamate from broken-down soy protein. Combined with inosinate (anchovy, katsuobushi, meat) the savouriness multiplies β which is why the sauces in Jjajangmyeon and Ramen taste as deep as they do. See Building umami.
When to add it
- Early, and reduced β the savouriness and colour penetrate. Braises like Gamja Jorim.
- At the end β the aroma survives. Finishing a stir-fry, dressing vegetables.
- Poured onto the hot pan directly β a burst of aroma, though prolonged heat drives it off and leaves only salt.
Storing
Room temperature unopened, refrigerated after. Left out it oxidises: the colour darkens and the aroma dulls. It is too salty to spoil, but the aroma definitely degrades β use it within six months of opening.
Substitutes
- Salt β replaces the saltiness only; no umami, no colour.
- Fish sauce β comparable savouriness, much stronger aroma.
- Coconut aminos β gluten-free, less salty and sweeter.