A pair of Chinese herbs is usually boiled twice, and the time for each boiling varies according to the herbs. For tonic herbs, the first boiling time should be more than half an hour, and the second boiling time should be more than 20 minutes. For herbs that clear heat and detoxify the body and treat superficial symptoms, the first boiling time is 20 minutes, and the second boiling time is about 15 minutes. For the more valuable herbs, they can be boiled three times, with the first boiling time being longer and the next two boiling times being gradually shortened, and the amount of water added gradually reduced. This is conducive to the full dissociation of the medicinal components of the Chinese medicine.