The process of decocting traditional Chinese medicine (TCM) involves many considerations. If the method is incorrect, it can not only affect the efficacy of the medicine but also impact our overall health. Today, I would like to share with you some important points to note when decocting TCM at home. Let's take a closer look.
【Avoid using boiling water to soak TCM】
Some people have the habit of soaking TCM in boiling water before decocting, thinking that this can shorten the decoction time and maximize the extraction of active ingredients. However, this is actually a misconception and lacks scientific understanding. Boiling water should not be used to soak TCM.
When TCM comes into contact with boiling water, the proteins it contains will coagulate and harden due to the sudden heat, forming a tight cell membrane on the outer layer. This inhibits the full extraction of internal components. High molecular substances in TCM can easily form colloids when exposed to boiling water, which also hinders the extraction of active ingredients. The powder left on the surface of TCM after cutting and grinding will undergo gelatinization due to the sudden heat, blocking the capillaries of the medicinal materials and making it difficult for water to penetrate. After the components dissolve, it becomes difficult for them to diffuse outward, ultimately affecting the extraction of active ingredients. Aromatic TCM, such as mint, perilla, magnolia, cardamom, and nutmeg, contain volatile oils and substances that are easily evaporated by heat. Therefore, boiling water should not be used to soak them, and they should be added later during the decoction process.
Generally, TCM is soaked in cold water before decoction for about 30 minutes. However, experiments have shown that the optimal water temperature for soaking TCM is 40℃ to 50℃. This condition allows the medicinal materials to be fully moistened and expanded, and improves the extraction rate of active ingredients.
【Should the pot be covered during decoction?】
To ensure that the sliced TCM is thoroughly decocted and that the active ingredients are fully extracted, it is recommended to cover the pot during decoction. This is especially true when the decoction contains components that can evaporate with steam, such as mint, patchouli, and cardamom. By covering the pot, the steam containing the volatile components of the medicinal materials condenses inside the lid and drips back into the decoction container as water droplets, reducing the loss of active ingredients.
For most solid roots, seeds, or animal-based medicinal materials, such as ginseng, astragalus, polygonatum, ophiopogon, schisandra, clam, dragon bone, and oyster, covering the pot during decoction can increase the extraction of active ingredients within a limited time, thereby enhancing the therapeutic effect of the medicine.
For loose and bulky medicinal materials such as loofah vine, Chinese rhubarb, polyporus, chrysanthemum, and mulberry leaves, the pot should not be covered during decoction as the liquid can easily overflow. Stirring should also be done regularly to ensure even decoction.
【Correct method of decoction】
Decocting TCM correctly can maximize its therapeutic effects. If a step is missed, it can affect the efficacy of the medicine and even lead to a significant loss of its effectiveness, resulting in reduced therapeutic effects. So, how should TCM be decocted?
1. Choice of container
The best containers for decoction are ceramic or clay pots, followed by stainless steel pots, enamel pots, and heat-resistant glass containers. These containers have stable chemical properties and are unlikely to react with the components of the TCM during decoction. It is important to avoid using iron, copper, and aluminum pots as these elements can react with certain components of the TCM, which is not conducive to the treatment of diseases.
2. Pre-processing
Step 1: "Inspect"
Before decoction, it is important to check the quality of the TCM. If there are signs of insect infestation or mold, immediate action should be taken to address the issue. Also, check if there are any specific requirements for the TCM that need special treatment.
Step 2: "Soak"
Soak the TCM in an appropriate amount of water for 20 to 30 minutes. The soaking time should be shorter for lightweight TCM and in higher temperatures, while longer soaking times are recommended for heavyweight TCM and in lower temperatures. The aim is to moisten the TCM and make it softer, facilitating the extraction of active ingredients.
3. Decoction
1. Water for decoction: Generally, as long as non-polluted tap water is used, it is recommended to avoid repeatedly using boiled water or overnight water for decoction.
2. Amount of water: As a general rule, the water level should be 3 to 5 cm above the surface of the medicine. The theoretical calculation is to add 10 mL of water for every 1 g of TCM. 70% of the total water should be used for the initial decoction, while the remaining 30% should be used for the second decoction.
3. Heating for decoction: It is generally recommended to follow the principle of "boiling first, then simmering". This means using high heat before boiling to quickly bring the water to a boil, and then switching to low heat after boiling to maintain a gentle boil and reduce water evaporation.
4. Decoction time: The decoction time is counted from when the water starts boiling. Generally, for heat-clearing medicine, the initial decoction should last 10 to 15 minutes, and the second decoction should last 10 minutes. For tonic medicine, the initial decoction should last 30 to 40 minutes, and the second decoction should last 25 to 30 minutes. Controlling the decoction time is important because prolonged high-temperature decoction can damage plant cells and increase the amount of insoluble and ineffective components in the decoction. Moreover, prolonged decoction also carries the risk of burning the medicinal material.
5. Number of decoctions: Generally, decocting two to three times is sufficient to extract 80% to 90% of the active ingredients in TCM. After decoction, filter the TCM water and drink it in multiple servings by mixing the decoctions from each round.
