Korean Soup Soy Sauce (gukganjang)
Guk-ganjang (국간장) is Korea’s traditional soup soy sauce. It is also called Chosun-ganjang (조선간장) a name used during the Chosun era and later adopted to distinguish it from Japanese-style soy sauce. This is one of the oldest seasonings in Korean cooking, used for centuries to season clear soups, stews, namul, and vegetable stir-fries.
Guk-ganjang looks very different from regular soy sauce. It is light in color, almost translucent, with a sharp, salty aroma. The clean color matters. It seasons broth without turning it dark, which is why Korean home cooks reach for it when making dishes like kongnamul guk, miyeok guk, or mild vegetable soups.
How It’s Made
Guk-ganjang is naturally brewed from meju blocks, salt, and water. Meju (메주) is the fermented soybean block that also becomes the base of Korean doenjang. During the long outdoor fermentation in Onggi jars, the liquid that forms becomes soup soy sauce. The remaining solids turn into doenjang. Because no wheat is added, guk-ganjang has a direct, intense umami flavor that comes purely from fermented soybeans.
Modern factory-made guk-ganjang follows the same basic idea but with controlled fermentation. You can find it in most Korean markets.
How to Use It
Use soup soy sauce only for broths, seasoned greens, and light dishes. A little goes a long way. Its saltiness is higher than regular soy sauce, so start with small amounts and adjust. For dishes that need deeper color or sweetness, use regular soy sauce instead.
Storage
Keep guk-ganjang in a cool pantry before opening. After opening, store it in the refrigerator to maintain its flavor. It lasts a long time when sealed well.
Substitutes
There is no perfect substitute. If you can’t find guk-ganjang, use a small splash of regular soy sauce and adjust the salt to taste, but the broth will be darker and the flavor less clean.
Where to Find It
Every Korean grocery store carries guk-ganjang. It’s usually placed near doenjang, gochujang, and other fermented condiments. Outside Korea, most Asian supermarkets stock it. You can also find it online from major Korean brands.
