Among these is cheonggukjang, a thick soybean paste made by fermenting steamed soybeans with rice straw, naturally rich in Bacillus subtilis, a probiotic essential to many fermented foods.

While Korean people have enjoyed cheonggukjang ㅡ fast-fermented bean paste ㅡ for centuries, little has been known about its origin. And, with its hazy root, there are few different names for ...