Dan Dou Chi (Fermented Soybean) (Fermented, oval, black, with a grayish-yellow film on top, often with a loose and porous outer skin)

【Name】

Dan Dou Chi (Fermented Soybean)

 【Source】

Classified as “Middle Grade” in the 別錄 (Bielu – Separate Records)

 【Frequency of Use】

D

 【Botanical Origin】

Prepared from the mature seeds of soybean *Glycine max* (L.) Merr. of the Fabaceae family, through processes such as cleaning, decocting in medicinal juice, steaming, and fermentation.

 【Characteristics】

Oval-shaped, slightly flattened, 0.6-1 cm long, 3-6 mm wide. The outer skin is black with slightly irregular longitudinal and transverse wrinkles, and a grayish-yellow film. The outer skin is often loose and porous, and some have fallen off, exposing the brown cotyledon. Brittle in texture, easily broken, the cross-section is lighter in color, with a musty odor and sweet taste.

 【Identification】

*Waitai Miyao* (外臺秘要 – Secret Essentials of the Imperial Library) states: “The fermented soybeans must be fresh; do not use old ones.” *Puji Fang* (普濟方 – Prescriptions for Universal Relief): “Dan Dou Chi (Fermented Soybean)… must be fresh to be good.” *Yifang Leiju* (醫方類聚 – Classified Collection of Medical Formulas): “The core of the fermented soybean is best when steamed and dried nine times.” *Bencao Gangmu* (本草綱目 – Compendium of Materia Medica): “For medicinal use, the central part of the large fermented soybean is the best.” Best when black in color, firm in texture, and sweet in taste.

 【Category】

Other