The choice of decoction apparatus is preferable to casserole, because the material of casserole is stable and does not chemically react with the drug ingredients, and its heat transfer is even and gentle. In addition, enamel pots, stainless steel pots and glass decocters can also be used. However, iron and copper pots cannot be used, mainly because they are chemically unstable and easily oxidized. The amount of water added to the decoction directly affects the quality of the soup. If you add less water, the decoction will be impermeable and the active ingredients will not be completely leached out. If more water is added, the decoction will produce more liquid, which is inconvenient for the patient to take the medicine. Chinese herbs have different textures, and their water absorption varies greatly, so the amount of water added is generally controlled at 5-10 times. The same weight of drugs, loose texture of its volume is large, water absorption is naturally more. If the texture is solid, the volume is smaller and the water absorption is less. Therefore, for decocting flowers, leaves and whole herbs, add more water. If you decoct mineral and shell drugs, add less water. The traditional method of adding water is to put the drug into the pot and add water to the first decoction to exceed the surface of the drug by 3-5 cm, and to add water to the second decoction to exceed the surface of the drug by 3 cm. This is because herbs from plants are mostly dried products. Soaking with water can make the herbs soften and restore their natural state after the tissue cells swell, so that the active ingredients can be easily leached out during decoction. Generally, for drugs mainly from flowers, leaves and stems, the soaking time is 1-1.5 hours. For drugs with roots, seeds, rhizomes and fruits, the soaking time is 2-3 hours. Multiple decoctions are more effective than one long decoction. Generally, the number of decoctions is twice or three times. Pay attention to the temperature of the decoction (called “fire” in Chinese medicine). It is customary to call it “wenhuo” or “wuhuo”). Wenhuo is a weak fire, where the temperature rises slowly and the water evaporates more slowly. The so-called martial fire is a strong fire, the temperature rises quickly, and the water evaporates quickly. If the decoction is too strong, the water evaporates quickly, which affects the leaching of the active ingredients and makes it easy to paste the pot. Conversely, a weak fire will make the decoction less effective. Generally, the fire is used before boiling, and then changed to civil fire after boiling, which can slow down the evaporation of water, which is conducive to the decoction of active ingredients. The decoction time should be determined according to the nature of the drug and the disease, as well as the condition of the drug. Generally, it takes 20-30 minutes for the first decoction to start boiling, and 30-40 minutes for the second decoction. For cold treatment, the first decoction takes 10-15 minutes, and the second decoction 15-20 minutes. For tonic drugs, the first decoction takes 30-40 minutes, and the second decoction takes 40-50 minutes. The amount of liquid retained: generally refers to the amount of liquid after a dose of medicine is combined by two decoctions. Adults take 400-600ml and divide it into two doses daily. For children, take 200-300 ml and divide it into two to three doses daily. Decoction of special medicine:The doctor will prescribe the medicine with footnotes in the prescription according to the patient’s condition and the nature of the medicine. (1) Decoction first: Generally, some minerals, shells and horny nails are not easy to be decocted because of their hard texture and active ingredients, so they are usually decocted for 30-40 minutes first, then mixed with other drugs and decocted. The common ones are raw gypsum, raw keel, mother of pearl, raw ochre, etc. Other toxic drugs are decocted first, and long decoction can achieve the purpose of reducing or removing toxicity. (2) after the drug: generally aromatic smell containing volatile oil or not easy to long decoction of drugs, to be put into the pot 10-15 minutes before the drug decoction. Common ones are Huo Xiang, Hooked Vine, Rhubarb, etc. Such as the vine alkaloids contained in hook vine, decoction time more than 20 minutes its antihypertensive components are easily destroyed. Rhubarb, the component with laxative effect to clear heat, is rhubarb glucoside, but it is unstable to heat and will decompose when heated for a long time. The laxative effect of rhubarb glucoside is stronger than that of glucoside, so it is not easy to decoct for a long time, and the method is mostly used afterwards. (3) packet decoction: generally seeds and pollen drugs, gauze bags into the group of drugs decoction. The common ones are psyllium, spineflower and so on. Such as psyllium easy to stick pot paste, coking. So it needs to be wrapped and decocted. Spineflower package decoction can avoid the lint off mixed into the soup liquid to irritate the throat. (4) Dissolve serving: take the drug after dissolving it with hot liquid. Common drugs are Xuanming powder, mannitol. (5) melting service; mainly some gum drugs, melted with hot liquid and then taken. If the mixed decoction will make the liquid viscous, affecting the leaching of other ingredients, gum drugs also have a certain loss, so the melting method of taking. The common ones are raw gum, deer horn gum, turtle plate gum. (6) Separate decoction to blend in, some valuable drugs should be decocted separately, and then blend the liquid into the medicine to take together. The common ones are ginseng, American ginseng, deer antler, etc. (7) Punching, some valuable drugs fine powder can not be decocted with the group of drugs, more use the method of punching to take, that is, the powder dissolved in the liquid medicine to take. This is not only conducive to the role of drugs but also can save herbs.