Quick-Fermented Soybean Paste

Where doenjang takes months of brick fermentation and aging, cheonggukjang is ready in days. Cooked soybeans are wrapped (traditionally in rice straw) and kept in a warm room, where Bacillus bacteria carried on the straw multiply and coat the beans in sticky, stringy mucilage. The Encyclopedia of Korean Culture notes that the vigor of the bacteria on the straw shaped the flavor. Once the beans have ‘caught,’ they are pounded briefly with salt, often with garlic, ginger and coarse chili powder, and kept for cooking.

The earliest written recipe appears in Jeungbo sallim gyeongje (1760), which describes fermenting new-crop soybeans on a heated floor for three days until threads form, then mixing them with roasted soybean powder and brine. The origin of the name is uncertain: the encyclopedia records explanations ranging from a wartime paste that could be made quickly (jeongukjang) to one learned from Qing China (cheongguk). By the 1939 cookbook Joseon yori beop, it had become the base of an elaborate stew with beef cuts, dried cod, abalone and sea cucumber.

Today it is mostly eaten as cheonggukjang-jjigae, simmered with tofu, kimchi, pork or beef and chili, and it is also sold dried and powdered. Many modern producers use selected starter cultures instead of straw.

• Whole-soybean nutrition: Because the beans are eaten whole, cheonggukjang is a source of plant protein, fiber, potassium, iron and folate; per 100 g, the Korean table lists about 21 g protein and 9 g fiber.
• Sticky mucilage: The threads contain poly-γ-glutamic acid, and the beans carry soy isoflavones. Laboratory and animal studies of these compounds are ongoing; claims for specific health effects are not established in people.
• Vitamin K2: Bacillus-fermented soybeans can contain menaquinone-7, a form of vitamin K2, and researchers have isolated it from cheonggukjang. Levels vary by product; people taking warfarin should keep their intake steady and talk with their clinician.
• Sodium: Seasoned cheonggukjang, especially the stew-ready type, is salty. Unsalted or powdered versions let you control the salt.
• Biogenic amines: Studies have found tyramine and other biogenic amines in some cheonggukjang samples at high levels, which can cause headaches or blood-pressure effects in sensitive people. Anyone told to limit tyramine should ask their clinician. Soy is also a common allergen.