A medicinal processing method whereby medicinal materials are heated until red hot by charcoal, coal, or the like, in order to make them crisp, soft, and easily crushed, and to facilitate the extraction of their active constituents in decoction. Materials such as dragon bone (Mastodi Ossis Fossilia, 龙骨lóng gǔ), oyster shell (Ostreae Concha, 牡蛎mǔ lì), gypsum (Gypsum Fibrosum, 石膏shí gāo), and chlorite/mica (Chloriti seu Micae Lapis, 礞石méng shí) that come in large lumps that do not crumble under heat are calcined by being placed directly in the fire. Materials such as hematite (Haematitum, 代赭石dài zhě shí), and pyrite (Pyritum, 自然铜zì rán tóng) that easily crumble are calcined in crucibles called dulu. Some materials such as borax (Borax, 硼砂péng shā), calamine (Calamina, 炉甘石lú gān shí), and alum (Alumen, 白矾bái fán) may be simply heated in a wok. Soft materials such as juncus (Junci Medulla, 灯心草dēng xīn cǎo) and old trachycarpus (Trachycarpi Stipulae Fibra Veta, 陈棕皮chén zōng pí) are calcined in a mud-sealed wok to char. Especially hard materials such as hematite (Haematitum, 代赭石dài zhě shí), white quartz (Quartz Album, 白石英bái shí yīng), pyrite (Pyritum, 自然铜zì rán tóng), tortoise shell (Testudinis Carapax et Plastrum, 龟版guī bǎn), and loadstone (Magnetitum, 磁石cí shí) are dipped in vinegar after heating to make them softer; actinolite (Actinolitum, 阳起石yáng qǐ shí) can be dipped in wine.