A bowl of decoction of Chinese herbal medicine is brewed, with a dark brown color, a cloudy appearance, and a bitter taste. When taken warm, there is often a muddy sediment at the bottom of the bowl. Due to the inherent color of the medicinal herbs, people rarely give it much thought when the decoction turns dark brown after brewing. As for the bitter taste, people often have the saying "good medicine tastes bitter," so the bitterness of the medicine is not seen as a bad thing, but rather a source of enjoyment. The cloudiness of the decoction is a source of confusion for many people, as they are unsure whether it is good or bad. As for the muddy sediment at the bottom of the bowl, whether to mix it with water or discard it is a practical issue that should not be underestimated, as it directly affects the efficacy of the medicine.
In order to determine whether the muddy sediment at the bottom of the bowl is to be taken or discarded when brewing Huang Lian (Coptidis Rhizoma) and Gan Cao (Licorice), a general introduction to the possibilities that can occur when these two herbs are brewed together will help make the correct choice. Modern scientific research has shown that the main active ingredients of Huang Lian are berberine and other alkaloids, while the main active ingredients of Gan Cao are glycyrrhizic acid and glycyrrhetinic acid. These two types of compounds have high solubility in water, so they can dissolve out from the herbal medicine slices during the brewing process. When these two herbs are brewed together, the berberine and glycyrrhizic acid from each herb may meet in the water and form salts or complexes with lower solubility in the liquid, resulting in the formation of fine granular solid particles suspended in the decoction, making it cloudy. If the decoction is left to settle, it may precipitate at the bottom of the bowl, forming a muddy sediment. Some experiments have been conducted, and it has been found that when Huang Lian and Gan Cao are brewed together with a larger amount of Gan Cao, the resulting decoction, when left to clarify, can become less bitter, but the antibacterial effect is significantly reduced. This indicates that berberine, which has a strong bitter taste and antibacterial effect, is precipitated in the muddy sediment. Therefore, if a prescription containing Huang Lian and Gan Cao is brewed together, the muddy sediment at the bottom of the bowl, if discarded, will obviously affect the efficacy of the medicine. The correct approach is to add a little water to the muddy sediment and mix it, then consume the turbid liquid. This is appropriate. Traditional Chinese medicine has many famous formulas that contain both Gan Cao and Huang Lian, such as Huang Lian Tang (composed of Huang Lian, dried ginger, cinnamon twig, Pinellia, Codonopsis, Gan Cao, and dates), Ge Gen Huang Qin Huang Lian Tang (composed of Ge Gen, Scutellaria, Huang Lian, and Gan Cao), and Shao Yao Tang (composed of peony root, Scutellaria, Angelica, areca nut, Huang Lian, rhubarb, patchouli, Gan Cao, and cinnamon). For the decoction obtained from these formulas, when the muddy sediment appears at the bottom of the bowl after being left to settle, it is advisable to mix it with water and consume it, or simply stir the entire bowl of decoction before consuming it. It is not recommended to discard it. The same method should be followed for other decoctions obtained from herbs that are brewed together.
Berberine belongs to the class of alkaloids, which are alkaline substances, and there are many Chinese medicinal herbs that contain alkaloids, such as Aconitum, Aconitum carmichaelii, Ephedra, Ledebouriella, Fritillaria, and Sophora flavescens. Glycyrrhizic acid is an acidic substance, and there are also many Chinese medicinal herbs that contain acidic components, such as Rheum palmatum and Prunus mume. When a prescription contains both herbs that contain alkaloids and herbs that contain organic acids, the decoction obtained from the simultaneous brewing of these herbs should also be consumed again if muddy sediment appears at the bottom of the bowl. On the other hand, alkaloids not only form insoluble salts with organic acids, especially large molecular organic acids, but also form insoluble complexes with tannic glycosides. There are many Chinese medicinal herbs that contain tannic glycosides. Although it has not been fully elucidated which insoluble substances formed between these herbs are effective or ineffective, for the sake of safety and to ensure efficacy, it is still advisable not to discard the muddy sediment, and it is better to consume it if possible.
Although ancient medical practitioners did not know which compounds could produce insoluble substances in water in the decoction of Chinese herbal medicine, or in other words, they did not understand the principle of the formation of sediment in the decoction, they had already noticed in clinical practice that the sediment should not be easily removed. One of the methods used was filtering the decoction. The purpose is to let the sediment enter the decoction for consumption. Even today, this method is still used, with only a layer of coarse gauze or mesh used for filtration. In short, when drinking Chinese herbal decoctions, although they may appear cloudy, there is wisdom in the cloudiness, and one should not try to make the decoction clear simply for the sake of appearance or ease of consumption. It is best to drink the entire decoction.
