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
pot with lid
ingredients whether they are herbs, minerals, or other substances
in which to pour decoction
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.
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
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.
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.
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.
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
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.
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:
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.
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:
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
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):
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.
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:
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.
- 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.
||李 敦 清 等 ： 《 方 劑 學 》 ， 上 海 上 海 中
醫 藥 大 學 出 版 社 ， 1 9 9 0 。
|| 段 富 津 主 編 ： 《 方 劑 學 》 ， 上 海 上 海 科 學 技 術 出
版 社 ， 1 9 9 5 。
|| 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。
||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
||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 。
||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 。
||梁 頌 名 主 編 ： 《 中 藥 方 劑 學 》 ， 廣
州 廣 東 科 技 出 版 社 ， 1 9 9 1 。
Professor, Beijing University of Chinese Medicine
Ph.D. Beijing Union Medical College
Vice Director, Gourmet Food Institute of Health Care and Nutrition
Angela Collingwood, MSN, Chief Editor, Integrated Chinese Medicine
Angelo Chung, B Pharm, Editor, Integrated Chinese Medicine Holdings