3-day fermented soybean paste, ammonia-pungent, slimy with stringy threads. Korean cousin to Japanese natto.
First recorded as jeonkukjang (戰國醬) in the Sallim Gyeongje (c. 1715, by Hong Man-seon) and the later Jeungbo Sallim Gyeongje (c. 1760); described as a quick soybean paste made when long-aged doenjang ran out. Traditionally fermented under straw blankets in heated ondol rooms.
Korean clinical research (Pusan National University, 2014) found cheonggukjang has 100x more nattokinase enzyme per gram than Japanese natto — the basis of its blood-clot-dissolving health claims. Andong's Hahoe Folk Village still ferments it under straw blankets the traditional way.
Khaki-yellow paste with whole soft soybeans in slimy strings, aroma of ammonia and old socks. In the bowl: stirred into anchovy stock with kimchi and tofu for cheonggukjang-jjigae. The smell drops away after the first spoonful; what's left is deep nutty umami.
Bacillus subtilis var. natto cousin (Bacillus subtilis ssp. cheonggukjang) ferments cooked soybeans at 40-45°C for 48-72 hours under straw or modern incubator. The bacillus produces poly-gamma-glutamic acid (the slimy strings) and breaks soy proteins into free amino acids and ammonia.
Variations
Andong-style (안동, straw-blanket ferment, the traditional benchmark), Yeongyang-style (slightly drier), modern incubator-fermented (industrial, milder), and the dry-powder cheonggukjang-garu (sold for diet shakes since the 2000s health craze).
On the Palate
Where Cheonggukjang sits in the Korean flavor cloud
Ingredients
Serves 6How it's made
4 steps · 3 hours 10 min active + 3 days 1 min waiting
- 1180 min
Cook 500 g soybeans 3 hr until soft; drain.
- 24320 min
Place warm beans in a straw-lined bowl; cover and incubate at 40 °C for 3 days.
Watch outHold the beans at a steady 40 degrees for three days — cooler and the bacillus stalls, hotter and it sours off.
- 31 min
Beans will develop stringy threads, ammonia smell — Bacillus subtilis fermentation.
Watch outReady when you lift a bean and it pulls long sticky threads and smells sharply of ammonia — that's the bacillus, not spoilage.
- 410 min
Pound coarsely with garlic + salt + gochugaru; use in jjigae.
