The term “wen huo” (文火) refers to a weak fire that is small and slow.
When decocting Chinese herbal medicines, there are considerations for the decocting fire, i.e., the difference between a Wen fire and a Wu fire. Martial fire refers to the fire that causes the temperature to rise and the water to evaporate rapidly, while its counterpart is the slow and weak fire, i.e., the gentle fire.
Generally speaking, thick flavored tonic medicines are suitable to be decocted for a long time with Wen Huo, in order to make the smell and efficacy of the medicines can be fully decocted, and will not be overly volatilized and lost due to the fire being too strong. The thin flavor of the antidepressant and heat-clearing medicine is suitable to be decocted rapidly with a strong fire.
When decocting Chinese medicines on your own, you should consult a Chinese medicine practitioner or a Chinese pharmacist first, pay attention to the size of the fire and the duration of the decoction, and do not decoct blindly on your own, so as not to affect the efficacy of the medicine.