What is a Decoction?

Understand what a Decoction is.

A Decoction is, in most respects, similar to an infusion in that the extraction method is by use of hot water.

Decoctions tend to be stronger than infusions because of the parts of the herb that Decoctions use are: roots, bark, seeds and berries, and generally woody parts of the herbs.  Because a Decoction is usually much stronger than an Infusion, the amount used to make each dosage of medicine is critical.

A Decoction is a method of extraction that is used for the parts of herbs that are generally woody and too hard to be extracted by the method Infusion.

A Decoction can often incorporate up to four or more herbs and can be a basis for making other medicines such as creams, liniments, ointments, etc.

History of Decoctions

The use of Decoctions in history seems to be a process that has been in place for thousands of years, a process that has also been used by the brewing industry here in Britain for again, thousands of years.

There is a great deal of folklore from the Highlands and Lowlands of Scotland supporting the use of herbs in general, that the clans made their own ales and beers was a part of the herbal processes, they would certainly have used Decoctions to extract what was needed out of the grain barley, barley is after all, the seed of the plant.

The Picts are known to have made ‘heather ale’ back in the early iron age, so water, heather, and probably barley were ingredients they knew and used early on to make ale.

Ale was an alcoholic drink made from grain, water, and sugar, this process produced yeast.   Most ale making houses were usually sited beside or near a bakery, the yeast produced being shared with the bakery to make bread.  Drinking ale was known to be healthier than drinking water, as most rivers were polluted, usually by the people who lived there as their wastewater, including cesspits, emptied into the rivers.

In medieval England (13th, 14th century) ale was extensively drunk, it provided nutrition and hydration, sadly also inebriation by some.  Some of the very poor couldn’t afford to buy ale and had to make do with what they could find, although most villagers made their own from the products of the fields.  Whereas the aristocracy could afford to drink imported wine, their servants who looked after them had to make to with ale.

Ales were made with grain of some kind, and the grain they used had to be Decocted, the constituents needed extracted.  This was done by first doing what was then called ‘mashing’, meaning the seed of the grain needed to be crushed and adding boiling water to begin the extraction, and by steeping for around 3 to 4 hours before adding honey or natural sweeteners such as Ash sap; sugar was imported therefore people used honey which is a natural product of the bees.

Hops (Humulus lupulus) are a natural preservative and part of the early use of hops was to preserve.  Hops were added directly to the cask after fermentation to keep it fresh while it was transported.  It was noticed that when ales containing hops had been left to mature for several months, the ‘ale’ had developed a depth of hop aroma and flavour.   This is how beer was made, the incorporation of the herb hops, added to ale made a big difference.   The constituents in the hops were extracted by immersion in ale, a way of Infusion rather than Decoction by the herb sitting in the ale for several months.  Hops are the flower of the herb Humulus lupulus.

Hops are a useful herb to consider when looking for a remedy for insomnia; beer or ale has the ability to make someone sleep, and it’s the content of hops that cause this effect.


Do I really need to drink this foul-tasting brownish liquid?

Dandelion root

Decoctions tend to taste unpleasant, mostly because roots, barks, etc. contain tannins, which have medicinal properties themselves, but most often decoctions result, not in a cup of water you can drink leisurely, but in a cup with a small amount of Decoction in it, which can then either be amalgamated with an Infusion or drunk on its own with a small amount of honey to sweeten the taste.  Decoctions can also be the basis for making other medications; having the ability to understand and make Decoctions is a required skill when considering making your own Herbal Medicines.

Despite the taste and the colour from the tannins that a Decoction ends up with, there are some good reasons for using Decoctions, and the primary reason is dosage.  If achieving a substantial change in the body to bring it to optimum performance or to help with a problem, it would be necessary to orally absorb difficult to eat herbal materials, in order to concentrate the constituents of such difficult to ingest herbs then they need to be concentrated, which is what a Decoction does.

Tannins are produced to a greater or lesser degree by all herbs.  Tannins are compounds that contract and astringe the tissues of the body, hence their use in the tannin process of leather, it binds and astringes the tissues of the leather making it soft and pliable.

Herbs containing tannin in good amounts are used to tighten up tissues such as varicose veins, drying up excessive watery secretions in diarrhea, to protect damaged skin, to stop bleeding during heavy menstrual flow for example, and to keep infection in check.   So when downing your first Decoction, keep this in mind, because the tannins that are causing the strong disagreeable taste are the ones you need to adjust your body to its optimum or to help to cure whatever it is you are treating.



The question of the role of trees fits nicely into the subject of Decoctions, as both tree bark and their seeds and leaves can be very useful, especially if the tree is local to where you happen to live.

Hawthorn berries

A tree bark, leaves, seeds, or berries are often some of the best healing parts of the tree, and as these are woody and hard the best way of gaining access to the constituencies we need is to make a Decoction of the parts of the herb.

When discussing the subject of herbs, it’s tempting to forget the place of trees with their healing properties, the most widely used medicines often originate from trees.

We have already discussed the place of the Willow (Salix alba) in Aspirin, but another that comes to mind is the Ash Fraxinus excelsior.  Both these trees are suitable for making Herbal Medications using the extraction method of Decoctions.

The ash tree once was the fourth common tree in Britain, sadly due to what is called ‘ash dieback,’ numbers of this well-known British tree are declining.  This not only will have a negative effect on the nature of the British landscape, but the Ash is also a source of Herbal Medicines, as well as having its place in the Folklore of many cultures in and around Europe.

Ash dieback is also known as Chalara, it’s a disease of Ash trees caused by a fungus called Hymenoscyphus fraxineus.  It causes leaf loss, crown dieback, and bark lesions in affected trees.  Once a tree is infected with the fungus it becomes weakened and will easily succumb to other pests, especially the fungi known as Armillaria or honey fungus.4

The first signs of Ash dieback in Britain were in a nursery in Buckinghamshire in 2012, and new cases are still being found.    The only way to keep it from spreading is by quarantining affected trees, although some effort is being made to grow saplings from Ash tree specimens that have so far been found not to be susceptible to this dreadful fungus.

Ash fruit (seeds)

The fruit of the Ash tree comes in the form of seeds that hang from the trees and are called keys here in Britain because that’s what they look like.  These keys were the source of many a child’s pleasure when thrown in the air to fall down like helicopters, of course, this is how the Ash tree grew to be so prolific in the first place, its seeds (keys) dispersed by the wind.

The Ash was Yggdrasil of Norse mythology, the Tree of the World, and of Healing.  One of three sacred trees to the Druids along with Oak and Hawthorn, certainly a highly respected tree in British history.

The bark of the Ash is pale grey in colour, which when cut exudes sap which the ancient Greeks called ‘meli’ or honey as it is as sweet as honey being made up of natural sugars.  Ash sap has a peculiar odour, it can be used as a gentle laxative, and can be used as a children’s laxative because of its gentle nature.  It is a nutritive and gentle tonic, usually operating very mildly, but in some cases can produce flatulence.  Usually given dissolved in an Infusion but can also be used added to a Decoction for a purgative where its sweet taste conceals the tannin taste of say, the bark of the Cascara sagrada.

Ash bark contains the bitter glucoside Fraxin, the bitter substance Fraxtin, tannin, quercetin, mannite, a little volatile oil, malic acid, and a certain amount of calcium.

Ash bark can be used as a bitter tonic, an astringent, to bring down fever, and relieving rheumatism of an arthritic nature, all of which are best made using Decoction as the extraction method.

The leaves and seeds (keys) of the ash tree have diuretic, diaphoretic, and mild purgative properties especially recommended for gout, rheumatics, and proving a useful substitute for Senna, having a less griping effect.

Leaves are best gathered in June and once dried will last up to a year if kept in a dark cool place, in a sealed container.

Not a tree coming readily to mind when considering Medicinal Herbs, but a tree that may well disappear from the British countryside; taking its herbal uses with it.  Certainly, a herb to make use of while we can.