How to Prepare Your Own Decoction

Traditional Chinese decoction is the process by which herbs are boiled and the remaining liquid is used for health purposes. Different decocting methods are employed depending on the nature of the substance and the individual’s state of illness, and it is very important to follow each step in the process correctly to achieve good results. Decoctions prepared incorrectly may impact on its intended effect in the body. Therefore, all Traditional Chinese Medicine (TCM) physicians have paid a lot of attention to how decoctions are prepared throughout the ages.

MATERIALS NEEDED:

Decocting pot with lid
Decocting ingredients whether they are herbs, minerals, or other substances
Water
Container in which to pour decoction
Filter or strainer

SELECTING THE DECOCTING POT:
Choosing the right pot is important for decoctions. A ceramic clay or crockery pot works best, but an enamel or glass pot can also be used. Iron, aluminum, and copper pots should be avoided because chemical changes occur and affect the original nature of the ingredients. The selected pot should be big enough to stir the ingredients and prevent the decoction from boiling over. A lid is necessary for optimal extraction because it stops water from evaporating too quickly.

USING THE RIGHT WATER:
Attention should be paid to the water used. Uncontaminated cool water, such as tap water, well water and distilled water are all appropriate. Ancient Chinese people made decoctions with running water, spring water, or the water in which rice had been washed. A TCM practitioner may recommend using wine or the combination of water and wine for certain types of decoctions.

GETTING STARTED:
STEP 1:
The amount of water used in decoctions depends on the quantity and characteristic of the substances and how long they need to be decocted. Before beginning your decoction, the ingredients whether they are herbs, minerals or other substances should be soaked for 20 – 30 minutes with cold water so the effective contents can be easily extracted when boiled. Fill the pot with water until the water level is 3-5cm higher than the ingredients.

STEP 2:
Heat control is another factor which must not be neglected. Ancient civilizations used a “quick fire” and “slow fire” at different times when decocting. For most decoctions, a simmering heat is used. If the herbal ingredients are overheated and become singed or charred, the whole decoction should be discarded because damaged ingredients can produce undesirable effects.

STEP 3:
The length of time necessary for making a good decoction relates to the properties and nature of the ingredients. For example, decoctions relieving exterior disharmony, which are commonly used for treating colds or influenza, and purgative decoctions are boiled for a short time with high heat and less water. Tonic decoctions are decocted for a comparatively long time (approximately an hour) with mild heat and more water. Diaphoretic herbs are usually decocted for 20 minutes. It is best to get the advice of a TCM practitioner as to what type of decoction you have and how long you should boil your herbal prescription in order to achieve the best health results.

STEP 4:
After the ingredients have been soaked for 30 minutes, they are boiled for the prescribed amount of time depending on your prescription and the advice of your TCM practitioner. The remaining liquid left in the pot should then be filtered or strained into another container (approximately one glass or 250 ml). The dregs (left over boiled ingredients) of the decoction should also be pressed in the strainer in to obtain the most effective and beneficial liquid from the extraction.

STEP 5:
Sometimes the same set of ingredients is boiled two or three more times. The remaining herbs left in the pot can be decocted a second or third time by adding less water, approximately 2-3 glasses of cold water (500ml), and repeating Step 4.STEP 6:
After preparation, the finished decoction is kept for consumption as prescribed. If the ingredients are decocted two times, you will have around two glasses (500ml) of liquid in your container. Generally, one glass is taken in the morning and the other is taken in the evening.

SPECIAL CONSIDERATIONS:The decoction of certain ingredients differs from the general procedure due to their special properties. TCM physicians or herbalists will usually tell you if there are ingredients contained in your prescription that have specific decocting requirements. These ingredients may also be packed separately in the prescription by the Chinese medicine pharmacy or store from which they were purchased. Decocting procedures for some select ingredients are as follows:

Ingredients that should be decocted first:
– Shell and mineral substances must be smashed to pieces and decocted first because they are hard substances whose active ingredients are difficult to extract. The remaining prescription substances should not be added to the decoction until the shells or minerals have been decocted for approximately 20 minutes after water boils.

– Some medicinal substances containing sand and mud such as the soil found in a furnace or Radix oryzae sativae and other bulky medicinal substances like reed rhizome and common self-heal fruit-spike (Prunella vulgaris) are also decocted first. Use their decoction liquid instead of water to decoct the rest of the ingredients.

Oyster Shell
牡蠣(介殼類)

peppermint
薄荷

Ingredients that should be decocted later:
– Volatile fluid and aromatic substances such as peppermint and costus root are added to the rest of the decoction ingredients towards the end of the cooking time and should be decocted for approximately 5 minutes.

Ingredients wrapped in gauze:
– Some substances like red halloysite, yellow starwort (Inula britannica) and Asiatic plantain seed will make the decoction turbid after being decocted, stick to the cooking utensil, or irritate the throat. These ingredients must be wrapped in gauze first, and then placed into the cooking pot to be boiled together with the other ingredients.

Asiatic plantain seed
車前子

antelope’s horn
羚羊角

Decoct some substances separately:
– Certain rare Chinese medicine substances such as antelope’s horn (Cornu saigae tataricae) and other more common substances such as American ginseng (Panax quinquefolium), should be cut into slices, and boiled separately from others to prevent their active ingredients from being absorbed by other herbs. Afterwards, their decoction can either be taken together with other decoctions or drunk separately.

Dissolution (melting by heat):
– Some medicinal substances like donkey hide glue (traditional Chinese tonic for nourishing the blood) and honey, etc. are colloid, sticky and easily dissolved. They should be melted separately from other ingredients and then mixed well with the rest of the decoction while they are still warm; otherwise, their stickiness will affect the decocting of other substances.

donkey hide glue
阿膠

musk
麝香

Take some substances with water:
– Some aromatic and rare ingredients like musk, bezoar and amber, which cannot be heated and decocted, should be ground to a fine powder and taken with a decoction or lukewarm water.

Fresh medicinal substances:
– Fresh ingredients that have not been dried, should be washed with water and then pounded to expel the juice. The juice can be taken either with water or a decoction.

chinese arborvitae kernel
柏子仁

Kernels:
– Kernels like wild Chinese jujube kernel, Chinese arborvitae kernel, apricot kernel and peach kernel should be crushed into pieces before decocting in order to get the best extraction from them.

References:

1.	李敦清等：《方劑學》，上海上海中醫藥大學出版社， 1 9 9 0 。
2.	段富津主編：《方劑學》，上海上海科學技術出版社， 1 9 9 5 。
3.	戴昭宇、趙中振主編：《日本傳統醫藥學現狀與趨勢》，北京華夏出版社， 1 9 9 8。
4.	郭天玲、朱華德主編：《現代中醫藥應用與研究大系（方劑）》，上海上海中醫藥大學出版社， 1 9 9 6 。
5.	李儀奎主編：《現代中醫藥應用與研究大系（中藥）》，上海上海中醫藥大學出版社， 1 9 9 5 。
6.	劉德軍主編：《方劑與中成藥學》，北京中國中醫藥出版社， 1 9 9 7 。
7.	梁頌名主編：《中藥方劑學》，廣州廣東科技出版社， 1 9 9 1 。

Written By:
Dang Yi
Professor, Beijing University of Chinese Medicine
Ph.D. Beijing Union Medical College
Vice Director, Gourmet Food Institute of Health Care and Nutrition of Beijing

Edited By:
Angela Collingwood, MSN, Chief Editor, Integrated Chinese Medicine Holdings Ltd.
Angelo Chung, B Pharm, Editor, Integrated Chinese Medicine Holdings Ltd.

Translated by:
Michael Yang