Chinese herbal decoctions are a traditional form of Chinese medicine, known for their rapid effectiveness and simple preparation. The quality of the decoction directly affects the clinical treatment outcomes. In addition to paying attention to issues such as cooking time, temperature, water volume, special cooking methods, warm or cold consumption, and dietary restrictions, the following three points should also be considered.
1. Avoid using boiling water for decoction
If boiling water is used directly for decoction, the surface starch and protein components of the Chinese herbs will suddenly gelatinize or coagulate due to the heat, hindering the extraction of these components. This also hinders the extraction of other active ingredients inside the herbs. The correct method is to first soak the herbs in cold water for a period of time (around 30 minutes) before decocting. This facilitates the infiltration, dissolution, and extraction of the active ingredients contained in the herbs. In urban areas, the water used for daily life is mostly tap water, which is neither rainwater nor river water but chemically treated water. To ensure the disinfection of water, tap water must contain a certain amount of residual chlorine. In areas with poor water quality, the residual chlorine content is even higher. Chlorine is a strong oxidant and can react with many organic substances. Since cold water has already been boiled, the residual chlorine has evaporated, avoiding its detrimental effects on the active ingredients. At the same time, during the heating process, the heavy carbonate salts of calcium and magnesium in the raw water decompose and precipitate, reducing the content of calcium and magnesium ions in the water. This reduces the chance of the active ingredients in the herbs combining and precipitating with calcium and magnesium ions, thereby increasing the concentration of active ingredients in the decoction. Therefore, it is better to use cold water for decoction.
2. Beware of false boiling phenomenon
Boiling is a basic requirement for preparing Chinese herbal decoctions, and a temperature of 100℃ is the standard for boiling. However, some herbal liquids start "boiling" before reaching 100℃. This is a physicochemical phenomenon caused by the chemical components contained in the herbs under certain conditions. For example, saponins and other chemical components can produce a large amount of foam at lower temperatures. In the decoction, if herbs such as Ziwan, Kuandonghua, Yuanzhi, Shashen, Tianqi, Niuxi, Gancao, and Jiegeng are combined, they are also prone to this phenomenon during decoction. The standard for determining whether the liquid has truly boiled is the temperature, not the surface phenomenon of foaming that people commonly associate with boiling. Liquid that has not been boiled means that the active ingredients in the herbs have not been fully extracted, which cannot achieve the desired clinical results and may cause other issues. Therefore, attention should be paid during decoction.
3. Proper administration
Whether the administration of Chinese herbal medicine is reasonable directly affects its therapeutic effect. For the medicine to take effect in the body, it must reach an effective blood concentration. Rational administration allows the body to maintain a balanced and consistently stable blood drug concentration, which is beneficial for the treatment of diseases. The common practice now is to separate the first and second decoctions for consumption. However, I believe this is not reasonable because the concentration of active ingredients in the first decoction is generally higher than in the second decoction, especially for herbs containing volatile and easily damaged active ingredients, which are present in minimal amounts in the second decoction. The difference in herb concentration directly leads to fluctuations in blood drug concentration, causing the medication to have varying levels of effectiveness, which hinders the treatment of diseases. The correct approach is to mix the first and second decoctions together and take them in multiple doses based on the condition.
