Infusions & Decoctions

Infusions and decoctions are simple methods of extracting the active constituents of herbs into hot water – infusions by pouring freshly boiled water onto light, aerial herbs and decoctions by simmering denser herbal materials. Short of nibbling the fresh herb, infusions and decoctions are the simplest forms of herbal preparation, and undoubtedly the oldest, probably trailing behind the discovery of fire by no more than a week or two!

They count amongst the few forms of medicine where the main pharmaceutical procedure is customarily performed by the individual at home – this being both their strength and their weakness. Compared to ready-to-use medicines, they are clearly inconvenient. However they are inexpensive, and there are many therapeutic strategies best served by them. Making this routine effort for the sake of one’s own health is therapeutic in its own right – a nurturing, reflective, connective, positive ritual. A herb tea as a customary ‘cuppa’ has a different psychological impact to taking a more obvious medicine such as a pill or a tincture for any duration.

One can and should take every opportunity to make infusions and decoctions from fresh herbs – although this presents practical limitations to the practitioner in terms of providing a regular fresh supply to patients (unless they happen to have them in their own gardens or hedgerows – it’s always worth enquiring). Inevitably dried herbs will be used in the main. The drying of herbs has for time immemorial been the most common method of preserving herbal remedies for future use, making it possible to employ them for twelve months of the year.

It seems appropriate in this section to dispense with the usual botanical names of herbs and to use common names throughout.

1. INFUSIONS

Description

Infusions, tisanes, or simply herb teas, they are one and the same. An infusion is the liquid preparation produced by steeping one or more herbs in hot water for a brief period of time, which is then strained, discarding the spent herb(s).

Infusions may be consumed piping hot or allowing to cool, but the latter should not be confused with cold Infusions, prepared in cold water, to be discussed later. In orthodox pharmacy, infusions may also include preparations that are subsequently preserved, but this will not be covered here.

Uses

Ordinary tea and cafetiere coffee are examples of herbal infusions. The herbal tea bags available in supermarkets and health shops are popular for their convenience and should be supported as part of a healthy lifestyle. However, they seldom contain top-grade plant material and can be expected to have no more than a mild therapeutic action (and in many cases none at all).

Infusions are often dismissed as being ‘weaker’ than tinctures and the like. This is not so. A standard 5ml dose of tincture is usually derived from 1 – 3g of herb, compared to 5 – 8g in an infusion. Even allowing for less efficient extraction, infusions still win the day. A 500mg capsule of dried herb, despite very efficient absorption, is clearly weaker still.

There are a number of circumstances in which infusions will prove the preparation of choice. A hot infusion is the ideal medium for promoting a therapeutic sweat. This often combines with another major advantage, of conveying volatile constituents rapidly to the tissues, especially the respiratory mucosa. Arguments abound as to whether infusions make better diuretics, or simply appear to be so due to the associated water intake. There is also a definite advantage to applying an alterative (‘blood-cleansing’) strategy in infusion form, where the image of ‘flushing out the system’ holds good in practice. It may seem illogical, but infusions taken hot are essentially cooling. This will be most obvious in the case of diaphoretics (which encourage sweating), but generally in energetic terms infusions (and decoctions) are favoured where a cooling effect is sought.

A choice must be made between infusing and decocting (see under). The guiding principle is that an infusion is suitable for leafy and other light herbs where extraction will be rapid, or where volatile constituents would be lost by lengthy exposure to heat. Decoctions are more suitable for roots, barks, and dense materials, or where constituents are stable to heat.

Infusions may incorporate as many as five or six different herbs, in proportions reflecting their relative potency and the balance of therapeutic activity required.

Formulation

For medicinal use, herb teas are usually dispensed loose either as simples or in combination. Self-fill teabags are available but add expense whilst proving only marginally more convenient.

The old herbalists’ approach of an ounce per pint per day, (roughly 30g per 500ml) divided into three or four equal doses, still holds good, if one accepts that this is effectively a maximum dose, often unnecessary and inevitably very strongly flavoured. The weight of herb is the only critical measurement – there is no reason why the volume of water should not be increased if this makes the result more palatable. This formula also assumed that the day’s supply would be prepared in the morning, and some or all would be taken cold, which is convenient but not always therapeutically appropriate.

Where a fresh hot brew is preferred at defined intervals, consider between one and four teaspoons per cup, depending on both the potency of the herb(s) employed, and whether they are fairly dense, e.g. Fennel seeds, or light, e.g. Marigold petals. It’s usually acceptable to ‘adjust to taste’ within sensible limits. Whenever there’s an opportunity to employ fresh herbs, one can instead talk in terms of a leaf, a sprig or a handful.

Modern domestic preference is for mugs rather than cups, containing about 250ml compared to a cup’s humble 150ml – but as already observed, the volume of water in which the herbs are infused really doesn’t matter.

Method

Dried herbs should be comminuted for use as teas (most commercial cut-and-dried herbs are). Needless to say, every care should be taken to ensure that the plant materials used are of high quality, have been stored carefully and remain within an acceptable shelf life. Where two or more herbs are to be infused, they should be mixed very thoroughly before proceeding further. Fresh herbs may need to be chopped or lightly bruised to aid extraction.

A measured amount of the fresh or dried herb(s) is placed in a clean teapot, and freshly boiled water poured over. The volume of water should slightly exceed that required in the final result to allow for absorption by the herb. The tea is allowed to stand for 2 – 5 minutes and then strained. The length of time will relate to the density of the herbs and their active constituents – as a general principle, unless a high tannin content is actually desired, too long an infusion will ‘stew’ the tea. The result may be taken hot or cold according to requirements.

Infusion cups, cafetieres, or any other suitable vessel with a close-fitting lid may also be employed, with the usual proviso that they are made from inert materials such as glass, china or stainless steel. It’s slightly less effective but still viable to simply infuse the herbs in a mug of water and strain it off into another mug. However, the Rolls Royce of the infusion world is the vacuum flask, (‘Thermos’), treated exactly as if it were a teapot, but being stoppered as soon as the boiling water has been poured on. This will result in infusion at a much higher temperature, volatile constituents are retained better, and the infusion time is reduced to a minute or two. One can also use a vacuum flask to store an infusion after it has been strained, in order to make a hot herb tea available later in the day.

Examples

As infusions are for many a first introduction to making herbal medicines, one or two examples are offered:-

Yarrow, Elderflower and Peppermint tea

Mix the three dried herbs in equal quantities. Use 2-3 teaspoons per mug, taken piping hot up to 5 times a day.

This famous mixture, re-invented in many cultures and used all over the world, is the great standby for head colds. Add Eyebright if catarrh is copious, or Thyme if the infection tries to drop to the chest.

Tea of Happiness

Mix 2 parts each Chamomile, Limeflowers & Vervain, 1 part each Lavender & Peppermint. Use 2-4 teaspoons per mug, taken as a hot drink as required.

A famous and much-loved recipe originating in Provence, Tea of Happiness can be used freely during the day for ‘free floating anxiety’ or during periods of excessive stress. It’s most popular use, perhaps demanding the higher dose, is as a safe but effective ‘nightcap’, promoting a restful sleep.

Spring Cure Tea

Mix Agrimony, Cleavers, Elderflowers & Nettles in equal parts. If some or all of these are available fresh, all the better. Infuse 30-50g in 1 litre water, allowing to cool. Divide into  4-5 doses a day, taken cold, the last not too close to bedtime as the effect is quite diuretic.

There’s a long tradition for taking cleansing herbs during the spring to clear out winter toxins, and employing some of the robust & nutritive ‘blood-cleansing’ herbs that arrive in the same season. The herbs (and there are others that you might choose) should be taken for a fortnight at the same time as a partial fast, concentrated on fruit and fresh vegetables, along with all opportunities that can be taken for communing with nature, spiritual cleansing and personal renewal.

2. COLD INFUSIONS

A cold infusion is prepared with cold water, traditionally steeped overnight. It goes without saying that cleanliness should be thorough under these circumstances, the risk of infection being high, particularly if mucilaginous herbs are employed, for which, perversely, the preparation is most commonly recommended. Keeping the infusing herb in a refrigerator will obviously help.

The most common subject is Marshmallow, the granulated root being steeped at approx 1:10 in cold water, and strained through a coarse sieve in the morning. A cold infusion of Valerian is a German favourite. Quassia is often preferred as a cold infusion whether as a bitter tonic or for external application to head lice. It can be re-infused several times over before any loss in its intense bitterness is apparent.

3. DECOCTIONS

Description

Decoctions are in most respects similar to infusions, and are employed for plant material too tough to yield their active constituents efficiently in an infusion. They are made by placing fresh or (usually) dried herbs in cold water that is brought to the boil and then simmered gently for 15 minutes or more.

In these times of pressing environmental issues a brief digression is needed to consider the carbon footprint of these hot-water preparations to, say, specific tinctures. Drying herbs in bulk in the UK will almost certainly demand some assistance from fossil fuels, or if importing from a hotter climate where air-drying is more viable, transport costs raise the carbon footprint instead. One should add to this the energy expenditure at home of heating water, although this may in part contribute beneficially to household heat and humidification. Tinctures, of course utilise ethanol – to deliver this to your door first grain has to be grown, processed and transported to the distiller, malting, fermentation and distillation then utilise significant amounts of energy, and the end product transported onwards. So, which has the larger carbon footprint, decoctions or specific tinctures? Hopefully there will be some academic research forthcoming.

Uses

Decoctions are suitable for roots, barks, large seeds & berries, and other dense material, or for lighter materials where maximum extraction is required of constituents (such as tannins) that are stable to heat. Some partially volatile remedies such as Wormwood and Aniseed, are sufficiently robust to survive the long exposure to heat satisfactorily.

Like infusions, decoctions may be taken hot or cold but in either case generally lend a cooling quality to the anticipated therapeutic strategy. One should be aware that remedies suitable to the decoction process tend to be therapeutically more potent than those used in infusions, so the dose may be more critical – overdosing with decoctions is common. A decoction may often incorporate four or more herbs, premixed in well-considered proportions.

One cannot resist mentioning the tradition for decocting remedies with oleaginous constituents in milk, (e.g. Fennel, Linseed, Peppermint) – milk being a naturally occurring emulsion with the ability to absorb both oil- and water-soluble constituents. The result will taste unusual, to say the least, and will not keep for more than a few hours.

Formulation & Method

Because roots, barks, etc. tend to contain powerful constituents, and the extraction of extended boiling is relatively efficient, for home preparation (e.g., by patients) the dose is less than for infusions – a standard would be 15g per 500ml per day divided into three or four equal doses. Higher doses might be considered if combining several remedies with a broad range of activities.

The herbs and water are placed in a lidded enamel or stainless steel saucepan, brought to a good rolling boil, covered and then simmered  gently for 15 minutes to 1 hour (according to the density of the material and the robustness of the constituents), and then strained. It is customary to add cold water to restore the original volume (e.g. 500ml) to aid consistent dosage. It sometimes makes sense to decoct very tough material for an initial period of an hour or more, then adding in lighter material for the last 15 – 30 mins.

A useful refinement, which minimises loss of volatile constituents (and avoids a kitchen full of steam!) is to use an electric ‘slow cooker’, the decoction time being increased to 2 – 4 hours.

Like infusions, decoctions can be made fresh for every dose and taken hot – and like infusions this may be preferred, for instance, to control a fever. However, in most cases, particularly as decoctions are quite time-consuming to produce, a supply for a day or more is usually made and thence taken cold. If care is taken to work cleanly at all stages, decoctions will usually remain viable in a domestic refrigerator for a week or more.

4. CONCENTRATED DECOCTIONS

A concentrated decoction can be made by simmering off further water from a decoction after it has been strained, whereafter it can be preserved as a stock remedy, or perhaps incorporated into complex products for internal or external use. It is only suitable for remedies that are sufficiently stable to heat. Formulation is largely a matter of common sense, an example being to start off with a normal decoction at about 1:20 which, having been simmered and strained, is then further reduced by simmering to 1:4 (e.g. 50g of herb decocted in 1 litre which is then reduced to 200ml). If 50ml of 96% ethanol is then added the result is a 1:5 preserved product of equivalent strength to a standard tincture. This formula would need to be adjusted accordingly if a lower strength of alcohol, (or perhaps glycerol), were to be employed as a preservative.

One is unlikely to concentrate a decoction further than 1:5 for any practical purpose – a 1:1 product or stronger is certainly possible but is so energy-inefficient that it cannot be recommended.

There’s another possibility to be mentioned here – that concentrated decoctions are almost guaranteed to be sterile on completion, and if they’re then placed in sterilised bottles and/or kept in the fridge, they can last for weeks without addition of preservatives before starting to ferment. Albeit a painstaking process, it’s possible that patients might be encouraged to use this form of preparation for themselves, but there’s a more fascinating prospect, echoing common practice in the Middle East even in present times, where the practitioner goes to the trouble of making concentrated decoctions for their patients.

5. COMBINED INFUSIONS & DECOCTIONS

There is no reason why the decoction and infusion methods cannot be combined in a single process, and this is often called for where roots and barks are to accompany lighter aerial herbs in a single remedy.

The roots or other dense material are decocted for up to an hour in the usual way, the lighter herbs being added at the last minute before removing from the heat and standing for a further few minutes before straining off.

6. DECOCTION VARIANTS – Back to the Future?

An overview of contemporary practice in the UK indicates that outside of using ready-made ‘phytopharmaceuticals’, the public will tend to use herbal infusions for self-treatment, whilst practitioners will tend to prescribe tinctures. This was not always the case! There used to be an extraordinary range of approaches to the basic concept of hot aqueous extraction – incorporating milk, wine, beer, mead or vinegar into the process, mixing infusions with decoctions, adding essential oils or resins as preservatives, even deliberately encouraging fermentation in the finished product before taking. In truth, decoctions were once subject to more wrinkles, local customs and ‘tricks of the trade’ than anything we see in modern herbal pharmacy. Changes in economics could easily bring any number of variants back, and if there is currently tremendous interest in experimentation with tincture-making, there will always be practitioners who either choose or need to look for something different. In particular you are commended to Cristina Cromer’s extraordinary article on Deep Decoctions here in The Herbarium.

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