Can Tap Water be Used to Brew Traditional Chinese Medicine?
We know that tap water usually needs to be treated with bleach or other disinfectants to ensure its safety for drinking, and it needs to contain a certain amount of residual chlorine (greater than 0.3 mg/liter). Chlorine is a strong oxidizing agent and can react with many organic substances. If this water is used to brew Chinese medicine, it will inevitably affect the efficacy of the active ingredients in the medicine, greatly reducing its effectiveness.
So, how can we remove the residual chlorine from tap water? The simplest and most effective method is to boil the water - during the heating process, the residual chlorine will gradually evaporate with the steam.
However, it is not recommended to use just boiled water (including warm water) to brew Chinese medicine. This is because using boiling water is not conducive to the penetration of water into the internal structure of the medicinal materials, hindering the extraction of active ingredients. This is especially true for Chinese medicines containing starch, such as Chinese yam, coix seed, and yam bean, which are more prone to starch coagulation, preventing the extraction of active ingredients.
Avoid Using Hot Water to Brew Chinese Medicine
If hot water is used directly, the surface starch and protein components of the Chinese medicine will suddenly heat up and become gelatinized or solidified, hindering the leaching of starch and protein themselves, as well as other active ingredients within the medicinal materials. The correct method is to soak the medicine in cold boiled water for a period of time (about 30 minutes), and then simmer it over heat. This helps the active ingredients in the Chinese medicine to infiltrate, dissolve, and extract. Tap water used by urban residents is mostly treated water, which is neither natural water (rain, fog, snowwater) nor ground water (river, lake, and underground water). In order to ensure the disinfection of water, tap water must contain a certain amount of residual chlorine, and the residual chlorine content is even higher in areas with poor water quality. Chlorine is a strong oxidizing agent and can react with many organic substances. As the boiled water has already evaporated the residual chlorine, it avoids the destructive effect of residual chlorine on active ingredients. At the same time, during the heating process of the water, the heavy carbonate of calcium and magnesium in raw water decompose and precipitate, reducing the content of calcium and magnesium ions in the water, thus reducing the chance of precipitation of active ingredients in the medicinal materials and increasing the concentration of active ingredients in the decoction. Therefore, it is best to use cold boiled water for brewing Chinese medicine.
The Correct Method is:
First, cool down the boiled water, then add the medicine and let it soak for a while (about 30 minutes), and then simmer it over heat. This will ensure that the active ingredients in the medicine are fully extracted, allowing the medicine to exert its intended effect. Of course, using boiled water or warm water for the second decoction is also acceptable.
How Much Water to Add for Brewing Chinese Medicine
1. Traditional Water Addition Method
Place the Chinese medicine in a clay pot, flatten it with your hand, and then add water that is 3-4 centimeters above the surface of the medicine. This method is the simplest and most convenient, but it is less accurate. If there are more flowers (such as Chrysanthemum, Honeysuckle, etc.) and leaves (such as Mulberry Leaf, Loquat Leaf, etc.) in the medicine, you can add more water as needed.
2. Water Addition by Measuring Device
Use a measuring cup or measuring cylinder to add water according to the different medicines and their first and second decoctions. Generally, for tonics and nourishing medicines, add 700-900 milliliters for the first decoction and 400-450 milliliters for the second decoction; for releasing exterior medicinal herbs, add 400-600 milliliters for the first decoction and 280-300 milliliters for the second decoction; for other medicines, add 500-700 milliliters for the first decoction and 300-350 milliliters for the second decoction. This method is more accurate than the traditional water addition method, but if there is a large quantity of medicine, the amount of water added will be less.
3. Water Addition by Weight
This method determines the amount of water added based on the total weight of the medicine. Weigh the prepared Chinese medicine (1 dose), and then add 65% of the total amount of water to the first decoction, leaving 35% for the second decoction. For example, for the tonic medicine Ginseng Nourishing Soup with a total weight of 150 grams, the amount of water added should be 1500 milliliters, with 65% added to the first decoction (975 milliliters) and 35% added to the second decoction (525 milliliters). This method is more accurate, especially for complex Chinese medicine formulas with large quantities of medicine. Although this method is more complicated than the previous two methods, it is more precise.
