Light soy sauce — the light, salt-forward, umami-driven everyday seasoning soy, thinner than dark soy. (The prized first draw of the ferment is specifically 'tou-chou' / head extract; commercial light soy is a blend of the first, second and third draws.) Cantonese seasoning default and the dipping bowl for steamed fish.
Recorded as 'jiangyou' in Song-era texts (~960–1279). The light/dark split is Cantonese practice — first-press liquid (sheng-chou) drained off after 6 months ferment, then the remaining mash sun-aged longer with caramel sugar to make lao-chou. Pearl River Bridge brand (Guangzhou, founded 1958) is the export reference.
Premium light soys are graded by amino acid nitrogen content — anything above 1.2g/100mL is 'tejí' (special-grade); Lee Kum Kee's Premium Soy and Pearl River Bridge Superior are both at 1.4g+. Below 0.8g is industrial blend, often hydrolyzed protein, not brewed.
Translucent dark amber — hold the bottle to light, you can see through it (dark soy you cannot). Salt-driven, clean, with a faint wheat-toast note. Splash a teaspoon over a steamed sea bass with ginger-scallion: that's the dish.
Roasted wheat + steamed soy + Aspergillus oryzae koji + brine, fermented 4–6 months. The first liquid pressed out is light soy: thinner, brighter, ~18% salt. Dark soy is made by further sun-ageing/concentrating the soy for ~2–3 more months and adding caramel colour (and often a thickener); it is darker, thicker and typically saltier than light soy, used mainly for colour. Substituting one for the other ruins both the flavor and the color of a dish.
Variations
Pearl River Bridge Superior (Guangzhou, export benchmark); Lee Kum Kee Premium (Hong Kong, slightly sweeter); Haitian Jinbiao (Foshan, the working-kitchen volume brand). Japanese usukuchi (Tatsuno) is the closest non-Chinese substitute.
On the Palate
Where Light Soy Sauce sits in the Chinese flavor cloud
Ingredients
Serves 6How it's made
4 steps · 30 min active + 185 days 1 hour waiting
- 160 min
Soak 1 kg soybeans overnight; cook tender; mash + mix with 1 kg roasted wheat flour.
- 27200 min
Inoculate with koji mold (A. oryzae); ferment 3–5 days at 30 °C for moromi mash.
Watch outHold the koji room right around 30 degrees for those few days — too hot and the mold sours, too cool and it barely takes; you want the beans to fuzz over evenly green-yellow.
- 3259200 min
Pack moromi in 20% brine; ferment in earthen jar 6–12 months, stirring weekly.
Watch outStir the moromi every week so the top doesn't dry or mold — you're looking for it to slowly darken and smell deeply savory, not sharp or off.
- 430 min
Press; filter; bottle the first-press light soy.
Watch outTake only the first liquid that presses out clear — that first-press run is the light soy; squeeze harder later and it comes out muddy and coarse.
