Practice and Principles
in making
Fresh Plant Tinctures  
Ken Atherton December 2007

Introduction

This document outlines the principles and practices used in the small scale production of Fresh Plant Tinctures (FPTs) from medicinal herbs.  

Large commercial medicinal herb manufacturers use broad acre grown dried plant material that is sourced from a global market. This along with increasing government regulation and control has led to the art and science of small scale and community produced herbal medicines prepared from locally grown herbs being little practiced. This has and is leading to an increasing loss of local know how in the production of medicinal herb extracts along with correctly identified medicinal herb species.

With climate change affecting agriculture globally and the increased demand for plant based medicines, the ability of large medicinal herb manufacturers to provide a continuing economic supply of medicinal herbs could be compromised. This would see the need for community based medicinal herb production with the accompanying knowledge base and genetic stock.

The author, a retired pharmacist, shares his knowledge and the experience gained in making FPTs over many years at Pindari Herb Farm.

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Pindari Herb Farm was established in 1981 and over the last 16 years has expanded its range of medicinal herbs within and around the gardens to over 100 species. The gardens also provide the author and his family with much of their food. There is a substantial but simple composting facility processing over one tonne of organic matter weekly, providing the basis for the health of the organic gardens. Further information on Pindari Herb Farm is at www.pindariherbfarm.com

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Details and information on the preparation of quality dried herbs is discussed elsewhere in such books as "Herbal Harvest" written by Greg Whitten and published by Blooming books (ISBN 1 876473 04 5). The preparation of tinctures and extracts from dried plant material likewise is not covered in this document, but it is of a similar principle in small scale production to that of FPTs.

At this time, the availability of ethanol (alcohol) is controlled in many countries. Ahead there may be the need to produce ethanol at a community level both as a fuel and as a means of preparing medicinal herb tinctures. Information on the equipment and procedures needed to do this safely may be obtained from the web page http://www.the-testament-of-truth.co.uk under the heading “Alternative Wind and Solar power.” (Distillation of spirits)

The opportunity that ethanol/aqueous extracts of fresh plant medicinal herb material provide as a means of healing is discussed briefly within this document and will be available ahead in detail on the Pindari web page at www.pindariherbfarm.com under “Quality Issues.”

Making FPTs is a simple and effective means of "capturing" and preserving/storing the medicinal properties of herbs. It needs to be noted that some herbs such as Pasque flower (Anemone pulsatilla) should not be made from the fresh herb. Always refer to Medical Herb text books for further information.

Definitions

• Comminution: The process of reducing size of the herb particles usually by pounding, grinding or cutting.
• Decoction: Extraction of the herb by simmering (gently boiling) usually in water.
• Expression: The process of forcibly separating liquids from solids.
• Exhaustion of herb material: Extraction of most or as much as possible of the herb.
• Glycetract: A tincture based on glycerin.
• Fluid extract: A concentrated aqueous and alcohol extract of herbal material of strength usually 1:1 or 1:2 (dry weight to menstruum)
• Fresh plant tincture (FPT): A tincture made from freshly harvested live plant material.
• Infusion: An extraction of water soluble components through the soaking in either hot or cold water. A "cup of tea."
• Maceration: The soaking of plant material in a menstruum.
• Marc: The plant material remaining after the extraction of the soluble components.
• Menstruum: A defined solvent or mix of solvents.
• Percolation: An extraction of soluble components via the passage of a menstruum through a column of plant material. E.g. "coffee percolation."
• Proof spirit: An alcoholic mixture of standard strength. - In Australia and Britain 57.1% alcohol by volume is a 100 proof spirit whilst in the US it is 50% alcohol.
• Succus: The juice of fresh plant material usually preserved with ethanol. E.g. Cleavers succus.
• Tincture: A aqueous/alcohol solution obtained by the extraction of an herb. Usually 1:5 (dry weight to menstruum) or 1:10 for more potent herbs such as Lobelia inflata.

Preparing FPTs.

To produce an FPT of optimum quality*, the objective should be to both capture the vital energetic life force (vibrational energy) and the required pharmacologically active components (chemicals) in the plant at a designated or optimum concentration.

*Quality also implying here, an FPT that captures those vibrational and material elements within the plant or part of the plant that facilitates a healing response and or symptomatic relief of dis-ease within the physical and mental and emotional states of a person.

This is best achieved by using freshly harvested and gently comminuted plant material grown under ideal conditions. This is then macerated in a calculated volume of a chosen percentage mix of alcohol in water that will facilitate the optimum solubilization of the pharmacologically active chemical components. Also, the immersion of freshly harvested plant material that is still energetically strong (alive) in an aqueous based liquid enables the vibrational energies of that material to be also transferred to the liquid

To standardize an FPT in Australia , the material substance within the plant (the dry weight) is measured against the total volume of liquids used in the maceration process. This is expressed as a ratio with the generally accepted standard strength of an FPT being 1:5 which is 1 part dry weight of plant material to 5 parts of macerating liquid.

Preparing FPTs is a balancing exercise between obtaining the standard dry weight strength of 1:5 and the recommended alcohol concentration. This is not always possible, as many herbs when fresh consist of 80% or more liquid. This is discussed in detail further on.

Whilst FPT’s are liquid alcohol and water extracts made from freshly harvested plant material, they are not homoeopathic mother tinctures, but being prepared from the fresh plant material they have the potential of capturing a significant proportion of the "life force" or homoeopathic energies of the plant along with the alcohol and water soluble components.

The FPTs manufactured at Pindari are prepared via the process of maceration for between 2 to 4 weeks using 4 litre glass jars which are stored in a cool room away from direct light. 

The expiry date applied is fours years from the date of maceration as it has been found after that period of time many FPTs start to lose their "zing." This is the word best used to describe the life force or vitality of the extract. This is discussed in further detail under “Quality Issues” in the document: “Energetic Considerations in the Pharmacy of Herbal Medicines.”

Containers and Equipment

When setting up to manufacture FPTs on a small scale, choosing a container of standard material, size and shape is recommended. Glass is the ideal container material with a size suggested between 2 and 4 litres and with a plastic lid of diameter between 70mm and 110mm. At Pindari a 4 litre glass container with rounded shoulders and with a 70mm diameter screw top cap is used.

After each use these are washed and scrubbed if necessary and then rinsed well. No detergents are used in the cleaning process as soap residues are difficult to remove. As the bottles are slow and difficult to dry and in order prevent bacterial and mould growth when stored, a small amount of alcohol is added to the clean wet jar which is then tightly capped. This sterilizes the jar and the alcohol residue is discarded just before re-usage.

The sharply rounded shoulders of the jar facilitates the "compacting" of the herb mass into the alcohol/water mix, holding the surface mass of the compressed herb at or below the surface of the menstruum within the jar.

Scales

An accurate set of scales that weigh up to 5 kilos and measures down to 1 gm are available for around AUD $200.

Funnel

This facilitates inserting the herb into the narrow mouth of the jar and can be purchased from catering suppliers.

Prod

This facilitates the pressing and compaction of the herb into the bottle.

Batch number Book and Labelling

For good manufacturing practice it is necessary that a written record be kept of each tincture prepared. Choose a well bound book and for uniformity and good practice, use a standard set of headings such as those listed below.

• Species and common name of herb and parts used.
• Batch number including date.
• Strength of extract and alcohol concentration.
• Previous batch number and date of manufacture.
• State, source and quantity of herb harvested.
• Measured dry weight of the herb.
• The weather conditions prevailing.
• Harvest procedure.
• Processing procedure.
• Calculations and quantities used of the herb, alcohol and water.
• The number of bottles prepared.
• General comments.
• Signature.

It is useful to choose a batch numbering system that incorporates the date so that the date of manufacture of any tincture can be readily obtained. E.g. Batch no. 211205A, being the day (21st), the month (Dec), the year (2005), and the number for the day (A). It can also be a reminder for the timing for next season's harvest and enables stock rotation and expiry date management. By numbering and using one page for each batch a ready reference is available for past batches and for quickly finding any given batch.

Also, by recording the quantities harvested when the macerating herb is pressed, along with current stock holding, details of the usage of that FPT is obtained that can be used to plan the amount of herb required for next season’s harvest.

Dry Weight Measurement.

The dry weight measurement is calculated by taking a sample of the herb a day or two prior to its harvest and processing. The sample should be cut into small portions or thin slices, then accurately weighed and dried with moderate heat (<45C) until "crackle" dry. When the "small twigs" in the sample break sharply is a good indication that the sample is dry. The weight of the dry sample should again be taken with the difference in weight being the weight of water that was present in the herb.
To calculate the dry weight percentage:

In practice the harvested herb starts to lose water immediately and increasingly so after comminution. In one instance on a warm day, in one hour a comminuted herb lost 6% by weight of moisture content. Thus it is important that the herb is processed and immersed in the menstruum as soon after harvesting as possible. This also reduces the amount of oxidation that occurs once the herb is cut, exposing it to air.

The dry weight of an herb can vary as much as 10% according to seasonal factors and weather, and the time of the day it was harvested.

Preparing the Plant Material.

Once harvested, all foreign matter should be removed. Generally aerial parts are not washed but roots should be thoroughly washed and their surface dried before they are comminuted. Any insect life should be removed either manually or by allowing them to "leave" over 1-2 hours of careful storage of the harvested material in a shaded, cool place. The herb is then comminuted to facilitate passive extraction of the soluble plant materials.

At Pindari a small chaff cutter with a 400mm diameter cutting wheel with three very sharp blades is used which is belt driven by a small electric motor. This gently and cleanly comminutes the herb material ready for maceration. The use of a chaff cutter requires great care and concentration in its use.

The milling of herb material is not used at Pindari in the belief that metal to metal pounding of herb material disturbs its subtle vibrational energies.

Many of the old pharmacopoeias discuss the identification of contaminants in commercial dried herb material, providing information on chemical and physical identification procedures. In small scale herb harvesting, contamination of the harvested material is easily avoided by close attention during the harvest and prior to comminution.

Macerating the Plant Material.

Place the macerating vessel in a secure position and add around 2/3rds of the calculated and pre-well mixed menstruum. Add the comminuted herb and press the herb well into this liquid. This ensures the herb is mixed with the menstruum and prevents compressed "dry" areas. The careful compaction of the comminuted herb enables the maximum amount of the herbal material to be mixed with the smallest quantity of menstruum. This provides the opportunity for obtaining a higher concentration of the herbal extract.

The rounded shoulder of the bottle further enables this compaction by holding the surface of the plant material under the liquid, also reducing the potential for oxidation.

Alcohol Concentrations.

There are established standard alcohol strengths for the menstruum for each herb. These may be obtained from the pharmacopoeias or by referring to current commercial products. 

The degree of solubility of the medically active chemical constituents within the herb decides the percentage of alcohol used as the menstruum. For example, the more oil content in an herb that forms a part of the active principles, the higher the alcohol strength used as oils are far more soluble in alcohol than water.

When using fresh plant material it is sometimes not possible to obtain the required alcohol concentration in the resultant FPT because of the high water content in the herb. In these cases, a compromise needs to be decided upon between the dry weight strength and the alcohol percentage of the resultant tincture. It is possible and sometimes appropriate, to partially dry the freshly harvested herb so that a portion of the water content of the herb is removed. This enables a higher alcohol concentration and or higher dry weight strength to be obtained. However there comes a point when drying the plant material that so much water and life force has been lost, that the resultant tincture ceases to be from fresh plant material.

A further understanding in the area of partially drying the herb can be obtained by working through the next “Calculations” section in this document.

It is necessary to maintain an alcohol concentration at least above 20% and preferable 25% to preserve the tincture against bacterial and fungal growth. 

Calculations for Preparing FPTs

In preparing an FPT, the weight of the herb to be used and the amount of alcohol and additional water required for the menstruum need to be calculated. In order to do this, four facts need to be known. They are:

1. The dry weight of the herb.
   From this can be calculated:
   1. The amount of fresh (wet) herb required to produce an FPT of a designated strength in a container of known volume.
   2. The amount of liquid (water) present in that quantity of herb.
2. The alcohol percentage required.
   From this and the known amount of liquid in the herb can be calculated:
   1. The quantity of alcohol required for the menstruum.
   2. The quantity of water needed for the menstruum.
3. The container volume.
   This may be dependent on the availability of containers of a suitable size and it is best to use a standardized container or multiples thereof. However the volume of the container chosen will be influenced by:
   1. The quantity of herb available to macerate.
   2. The quantity of FPT required to be produced.
4. The strength of the FPT to be prepared.
   In this document the strength of 1:5 (dry weight of herb to total liquid) is set as a standard but this is variable. In general it is best to produce as strong an FPT as practicable and repeatable. Factors that influence this are:
   1. The intended use of the FPT and dose considerations.
   2. The dry weight, therefore the percentage of water present in the herb.
   3. The nature of the herbal material and the degree of comminution of the herb as some herbs are more easily compressed than others.

When the above have been established it is then necessary to check if the quantities involved will produce an FPT of the chosen strength and alcohol concentration and that it will actually fit into the container. A demonstration of this is given below.

Example 1

Motherwort (Leonurus cardiaca) harvested 27th of December 2001. Batch Number 271201A

1. 33% dry weight
2. 25% alcohol menstruum
3. 4 litre bottle
4. 1:5 strength

THE CALCULATIONS STEP BY STEP ARE:

1. A 1:5 strength being 1 part (dry weight) of herb into 5 parts of menstruum gives a total of 6 parts. Divide 6 into 4000mL and this will provide the dry weight of herb needed.
   6 divided into 4000L = 666gm. This can be rounded off to 660gm (dry weight).
2. The weight of fresh (wet) herb to be used can then be calculated by multiplying the dry weight figure by the inverted dry weight percentage.
   660gm multiplied by 100 and divided by 33 = 2000gm of fresh herb needed.
3. In 2000gm of fresh (wet) herb there is 660gm of dry matter and 1340mL of water.
4. The volume of the menstruum required is obtained by multiplying the dry weight by 5 this will provide the total volume of menstruum needed to make an FPT of strength 1:5.
   660gm X 5 = 3300mL total volume of menstruum.
5. The amount of alcohol needed in the menstruum is 25%. Multiply the total liquid content by the percentage of alcohol
   3300 X 0.25 (25%) = 825mL of 100% alcohol.
6. To calculate the amount of water to be added to the menstruum, take the total volume of the menstruum and subtract the amount of liquid in the herb and the alcohol required.
   3300mL – 1340mL – 825mL = 1135mL water to be added.
7. To check if these fit into a 4000mL bottle add the amount of wet herb to the volume of alcohol and water to be added to see if it does not exceed the bottle’s capacity.
   2000gm + 825mL + 1135mL = 3960mL/gm which fits into a 4000mL bottle

If using 96% alcohol then the volumes to be used are:

Amount of water to be added is:

Thus the volume of water required is 1101mL to be mixed with the 859mL of alcohol (96%).

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Any herb with a dry weight of 20% is a 1:4 (dry wt) in its own liquid and it is not possible to add sufficient alcohol to the macerating herb to reach the required alcohol percentage and still obtain a 1:5 (dry wt) standard strength. Even with an herb with a 25% dry weight, it is difficult to obtain a 1:5 (dry wt) especially if a menstruum with an alcohol strength greater than 25% is required.

In these cases a decision can be made to either partially dry the comminuted herb or produce a weaker resultant tincture of say a 1:6 or 1:8 (dry wt strength)

In warm conditions and with an air flow, a comminuted herb loses water quickly and this can be judiciously used to reduce the water content of the herb. It needs to be managed by measurement so that both the required alcohol and dry weight strength can be obtained. 

Each FPT of an herb is unique with no two herbs being the same and in order to successfully make FPTs from many different herbs it is necessary that the principles of the calculation methods are understood rather than any given formula.

It has been found in practice during Medicinal Herb Seminars that with hands on experience, the calculations are readily and easily understood. 

Examples of Calculations for Preparing FPTS:

FOR HERBAL STRENGTHS WEAKER THAN 1:5     i.e. 1:6 - 1:7 - 1:8 etc.

Here it is necessary to do some trial calculations. By knowing the dry weight of the herb and the required alcohol concentration you can by calculation as given above, work out if it will fit in your chosen container. Remember, the alcohol concentration is important for the adequate solubilization of the herb material to be extracted.

As mentioned previously you can consider drying the herb for 1-2 hours to reduce the water content but this should be measured, and it should also be noted that some herbs oxidize rapidly and need to be tinctured as soon as practicable after being comminuted.

This is also where your batch record book is useful for referral to the previous time you prepared an FPT of a herb.

Example 2. The preparation of White Horehound (Marrubium vulgare) fresh plant tincture.
Batch Number 240301A

The dry weight was calculated to be 18%.
By trial 2900 gm of the herb was able to be fitted into the bottle giving a dry weight content of
2900 X .18 = 522 gm and a aqueous content of 2378mL.
The amount of alcohol added was 1000mL of alcohol (100%).
thus the total volume of liquids present was 2378mLs + 1000mL = 3378mL
thus the strength of the tincture was 3378 divided by 522 =  1:6.5

In this case the strength of the tincture was held high considering the dry weight of the herb and the optimum strength of the alcohol menstruum was increased from 25% to 29.6%.

When next preparing this herb, it could be air dried for an hour or so and the alcohol concentration reduced with the addition of a calculated amount of water.

FOR HERBS WHERE THE DRY WEIGHT IS 40% OR MORE.

Example 3. An FPT was prepared from the fronds (leaves) of Rosemary. The preparation was complicated by the harvest directly after a little rain where the fronds were wet. These were partially dried for a night and a day before tincturing.

(This example shows that when the dry weight and the quantities of alcohol and water are known, by systematically working through the calculations, an accurate strength of the resultant FPT and its alcohol concentration can be obtained.)

A sample of the herb was collected immediately following harvesting and found to have a dry weight of 40%, a further sample was taken just before maceration of the partially dried herb and found to have a dry weight of 60%. The drying of the herb resulted in a 20% reduction in moisture content.
As more herb had to be harvested to complete filling a second 4 litre bottle, a third sample for the dry weight of this sample was taken and found to be 40%.

Bottle 1 - 1320 gm of herb was placed in the bottle at a dry weight of 40%. As the dry weight was unknown at the time, it was assumed at 50% and the calculations were:

NB. It is best to always do a dry weight calculation first if possible.
Thus to 1320 gm of wet herb 1980mLs of alcohol 100% and 660mLs of water were added.
You will note that if the numeric quantities (1320 gm herb + 1980 mL alcohol + 660 mL water) are added it comes to 3960 which suggests they will fit into a 4 litre bottle.

Bottle 2

With the second bottle 1145 gm of herb were added plus 170 gm of freshly harvested herb to fill the 4 litre bottle. This amount of herb allowed for the compression of the herb mass sufficiently for the 1980mLs of alcohol 100% and 660mL of water that was added to cover the herb material.

Final calculations

Knowing the dry weights, the accurate calculations for the strength and alcohol concentration of the combined pressings from bottle 1 and 2 can be completed.

Totals