Borgmann Aquaponics Hydroponics
Tincture – Alcohol Extract
The tincture is the most versatile of all herbal extraction methods. Ethanol as a solvent simultaneously accesses water-soluble and fat-soluble ingredients – a spectrum that neither an oil extract nor a tea extract alone can achieve. The European Pharmacopoeia (Ph. Eur.) defines the tincture as an official dosage form and specifies precise ratios, alcohol contents, and testing methods. For home use, it is also the most accessible method for producing concentrated, long-lasting herbal preparations – if one understands the chemistry of the solvent.
Physical-Chemical Principles
Ethanol as a bridge molecule between two worlds
The crucial advantage of ethanol over water and oil lies in its molecular dual nature. The ethanol molecule (C₂H₅OH) possesses a polar hydroxyl group (-OH), which makes it miscible with water and polar substances, and a non-polar ethyl group (-C₂H₅), which imparts affinity for lipophilic compounds. Ethanol is therefore an amphiphilic solvent: It simultaneously dissolves water-soluble compounds (glycosides, tannins, organic acids, flavonoids, mucilages) and fat-soluble substances (essential oils, resins, bitters, fat-soluble vitamin fractions). No other common solvent offers this broad spectrum while being physiologically compatible and having a preserving effect.
The selectivity of ethanol can be precisely controlled via the concentration of the menstruum – the pharmaceutical term for the extraction solvent. As the ethanol concentration increases, the solvent affinity shifts from polar to non-polar: Dilute ethanol (30–40 %) preferentially accesses water-soluble fractions; concentrated ethanol (70–96 %) increasingly dissolves lipophilic substances. This is not a coincidence but a direct consequence of the Hildebrand solubility parameter: Ethanol-water mixtures have a solubility parameter that continuously shifts between that of water and that of pure ethanol – each time optimally capturing a different part of a plant's active compound spectrum.
Choosing the concentration – the most important lever in tincture making
The choice of ethanol concentration is the most significant decision in the production of a tincture. It determines which substance classes are extracted – and which remain in the plant material. The following overview is a summary of the proven standard values in practice:
| Ethanol content | Preferentially dissolved substance classes | Typical application |
|---|---|---|
| 25–35 % | Mucilages, polysaccharides, mineral salts, some glycosides | Cough extracts, marshmallow root, lime blossom |
| 40–50 % | Flavonoids, tannins, saponins, enzymes, water-soluble glycosides | Hawthorn, valerian (partially), lemon balm |
| 60–70 % | Bitters, alkaloids, essential oils (partially), resins, lipophilic flavonoids | Standard range according to Ph. Eur. and DAB; arnica, chamomile, peppermint |
| 80–96 % | Resins, waxes, chlorophyll, strongly lipophilic terpenoids, coumarins | Propolis tincture, cinnamon bark tincture, essential oil concentrates |
For most medicinal plant tinctures, a range of 45–70 % is ideal – it captures the broadest spectrum of active compounds and corresponds to the recommended range of the German Pharmacopoeia (DAB) for standard tinctures. For home use, high-proof potable alcohol (e.g., grain spirit or vodka at 40 %) is an acceptable compromise for simple applications; for reproducible pharmaceutical quality, pharmacy-grade ethanol (96 %) with targeted dilution to the desired concentration is the better choice.
Diffusion, equilibrium, and percolation – extraction thought through to the end
As with oil extraction (Article 1 of this series), diffusion is also the driving force in tincture making: active compounds migrate along a concentration gradient from the plant cells into the solvent. Extraction stops once a concentration equilibrium is reached between plant material and menstruum – not when all active compounds have transferred. This is a crucial difference. According to the pharmacopoeia (Ph. Eur., Chapter 4.1.1), a standard 1:10 tincture corresponds to a mixture of 1 part drug in 10 parts menstruum; the more concentrated 1:5 variant (1 part drug in 5 parts menstruum) yields a correspondingly higher-concentrated tincture.
To overcome the equilibrium limit and achieve an exhaustive extraction, industrial pharmacy uses percolation: The menstruum continuously drips from above through a percolator vessel in which the plant material is packed tightly, and flows out saturated at the bottom. Because fresh, unsaturated solvent constantly flows in, the concentration gradient is maintained permanently. Under optimal conditions, up to 95 % of the extractable ingredients are captured – compared to typically 60–70 % with simple maceration. For home use, a simplified percolation setup using a funnel, cotton wool, and a graduated collection vessel can be built; the apparatus requires some practice but is, in principle, achievable without special tools.
Alcohol as a preservative – the shelf life of the tincture
From an ethanol content of approx. 18–20 %, microbial growth (bacteria, molds, yeasts) is effectively inhibited. From 40 % upwards, the tincture is considered completely microbiologically stable. This is why correctly prepared tinctures, when stored at room temperature and protected from light, have a shelf life of several years – a significant advantage over aqueous extracts (teas, infusions), which spoil within 24–48 hours. When using fresh plants, it is important to note that their water content significantly lowers the ethanol content of the menstruum: Fresh plants can contain up to 80–90 % water, which dilutes the ethanol concentration during maceration. To maintain the target ethanol content of the finished tincture, the water content of the fresh plant must be calculated and the menstruum correspondingly concentrated higher.
Plant-Specific Characteristics – why concentration and ratio vary
The recommendation "50 g plant in 200 ml alcohol" is a good starting point, but not a universal formula. Active compound localization, cell density, water content, and the chemical nature of the target substances require an adapted approach for each plant.
Valerian (Valeriana officinalis)
Valerian root contains valerenic acid and valepotriates (iridoid monoterpenes) as primary active compounds, as well as essential oil. Valepotriates are extremely unstable: They decompose in aqueous environments and under heat within hours. Recommended menstruum: 70 % ethanol, as this level stabilizes the valepotriates while also effectively extracting the essential oil. Fresh plant tinctures (from freshly harvested roots) are considered the gold standard here, as valepotriates are partially degraded during the drying process. The ratio is typically 1:5 (fresh plant). The finished tincture has a characteristically strong odor – a sign of the essential oil and isovaleric acid, not of spoilage.
Arnica (Arnica montana)
Arnica tincture is one of the oldest and best-documented topical applications in phytotherapy. The sesquiterpene lactones (helenalin and derivatives) are moderately lipophilic and are optimally extracted with 70 % ethanol. The DAB prescribes a ratio of 1:10 for Tinctura Arnicae. An important practical note: Arnica tincture at its original concentration (1:10) irritates sensitive skin – it is typically diluted 1:3 to 1:10 with water for application. Applying undiluted tincture to wounds or mucous membranes is a common mistake that can cause chemical burns. In case of asteraceae allergy (arnica, chamomile, chrysanthemum), a skin test is mandatory before use.
Echinacea (Echinacea purpurea / pallida)
Echinacea tinctures are a prime example of how the plant species and part significantly determine the optimal menstruum. From E. purpurea herb, primarily polysaccharides and caffeic acid derivatives (chicoric acid) are obtained – for which 55–60 % ethanol is ideal. From E. pallida root, the primary active compounds are alkylamides and lipophilic ketoalkenes (ketopolyenes), which require 65–70 % ethanol. Anyone who uses "just Echinacea" without knowledge of the species risks an extract that either accesses the wrong fractions or leaves valuable compounds behind in the plant material. Commercially, the two species are sometimes confused or mixed without declaration – a quality problem repeatedly documented in comparative scientific studies.
Roots in general (licorice, comfrey, lovage)
Root drugs place special demands on preparation and extraction time. The dense cell tissue and high lignin content lead to slow diffusion; roots should therefore always be finely cut or ground (particle size 2–4 mm). The maceration time is at least 4 weeks, for uncut pieces rather 6–8 weeks. For licorice root (Glycyrrhiza glabra) with its water-soluble triterpene saponins (glycyrrhizin), 30–40 % ethanol is the most effective range; for comfrey root (Symphytum officinale), which contains allantoin and pyrrolizidine alkaloids, special caution is required: Pyrrolizidine alkaloids are hepatotoxic and carcinogenic, making comfrey tincture acceptable only for short-term topical application – internal use is to be rejected for safety reasons.
Step-by-Step Instructions
Standard value according to DAB: 50 g dried plant material / 250 ml menstruum (1:5). For fresh plants: 100 g fresh material / 200 ml menstruum (approx. 1:2).
Determine the target concentration (see table above). Mix high-percentage ethanol with distilled or boiled water. Formula: Volume of 96 % Eth. = (Target concentration × Total volume) / 96. Example for 60 % from 96 %: 625 ml of 96 % + 375 ml water = 1 liter of 60 %.
Dried material: roughly tear leaves/flowers; finely chop or grind roots/barks (2–4 mm). Fresh plants: process immediately after harvest, chop finely. For fresh plants, estimate the water content and concentrate the menstruum correspondingly higher.
Place plant material in a clean screw-top jar, pour menstruum over it. Ensure the material is completely covered. Seal the jar tightly – ethanol evaporates quickly with leaky lids, significantly altering the concentration. Label the jar: plant, menstruum concentration, date, ratio.
Cool (15–22 °C), dark, shake or swirl daily. Duration: flowers/leaves 2–3 weeks; roots/barks/seeds 4–6 weeks. The color and smell of the menstruum will visibly change – this is the quality signal of ongoing extraction.
Pour the contents through a muslin cloth and press the plant material firmly (noticeably increases yield). Second filtration through a coffee filter for a clear product. Filter at room temperature – do not heat, as ethanol is volatile.
Fill into dark glass bottles with dropper insert (facilitates metered application). A small air gap in the bottle neck is normal; do not overfill the bottle. Label completely.
Dilution, Dosage, and Legal Limits
Alcohol in the tincture – how much is how much?
A 1:5 tincture in 60 % ethanol contains about 18 µl of pure alcohol per drop (approx. 30 µl). With a typical single dose of 20–40 drops, this corresponds to approx. 0.4–0.7 ml of pure alcohol. For adults, this is generally harmless; however, for children, pregnant women, people with liver diseases, and individuals in alcohol abstinence, alcoholic tinctures are not suitable. Glycerin-based extracts (glycerites) or aqueous extracts (infusions, Article 5 of this series) are available as alternatives.
Dilution for topical application
Undiluted tinctures are usually too concentrated for direct application to the skin. Guideline values for topical dilution:
- Arnica tincture 1:10: dilute with water 1:3 to 1:5
- Calendula tincture 1:5: dilute with water 1:2
- Propolis tincture: 10–20 % in solvent or cream
Legal framework for home use
The production of tinctures for personal use is generally permitted in Germany and Austria. As soon as tinctures are given to other people – even free of charge – they are subject to the German Medicines Act (AMG) and may not be placed on the market without pharmaceutical authorization. For giving to acquaintances or as a gift, assuming the recipient's personal responsibility, the transfer in small quantities within a private environment is legally gray – but commercial distribution is clearly prohibited without authorization.
Sourcing ethanol for home use
Undenatured ethanol (for food or pharmaceutical use) is only available in pharmacies in Germany and is subject to taxation (spirit tax). For home use, high-proof potable alcohol (grain spirit 38–40 %, vodka 40–70 %, rectified spirit up to 95 %) is often used. Denatured ethanol (methylated spirits, isopropanol) is absolutely unsuitable for internal or topical tinctures and poses a health risk.
Storage & Shelf Life
- Dark glass: Light exposure promotes oxidation and degradation of light-sensitive active compounds (hypericin, flavonoids, carotenoids). Brown or blue glass is mandatory.
- Room temperature (15–22 °C) is sufficient. Refrigeration is not strictly necessary but extends shelf life. Freezing is not recommended, as temperature fluctuations during thawing can lead to precipitations.
- Shelf life: Correctly prepared tinctures with over 40 % ethanol – when well-sealed, dark, and cool – are stable for 2–5 years. Tinctures with less than 25 % ethanol should be used within 6–12 months.
- Precipitations upon standing (especially in tannin- and resin-rich tinctures) are not a quality defect. Shake before use; if cloudiness is bothersome, filter again through a coffee filter.
- Dropper insert: A small opening reduces evaporation and facilitates accurate dosing. Pipette bottles are ideal for tinctures with single doses under 1 ml.
Quality Signals and Common Mistakes
Positive quality signals
- Intense, plant-typical color of the extract (calendula: orange-yellow; arnica: golden-brown; St. John's wort: dark red).
- Characteristic, plant-typical odor without foreign notes.
- Clear or slightly cloudy (due to tannins or resins) liquid – no mold, no streaks, no sediment clumps.
Common mistakes
- Alcohol content too low: Shot glass tinctures made with simple fruit brandy (20–30 %) extract only a fraction of the active compounds and are less microbiologically stable.
- Loose closure: Ethanol evaporates quickly. After just one week in a poorly sealed jar, the concentration can drop noticeably – impairing extraction efficiency and shelf life.
- Fresh plant directly with 40 % alcohol: The water content of the fresh plant lowers the effective alcohol content of the mixture to 20–30 % – this guarantees neither optimal extraction nor adequate preservation.
- Wrong alcohol: Denatured spirits, isopropanol, or methanol are forbidden for tinctures of any kind and are life-threatening.
Further Specialized Literature
- European Pharmacopoeia (Ph. Eur.), Chapter 4.1.1: Tinctures (Tincturae). EDQM Strasbourg; continuously updated. — Binding definition of ratios, ethanol contents, and testing methods for standard tinctures; publicly accessible as a monograph.
- German Pharmacopoeia (DAB), current edition. Deutscher Apotheker Verlag / Govi Verlag. — Contains national monographs for Tinctura Arnicae, Tinctura Valerianae, and others with quality standards for drug-alcohol ratios.
- Blaschek W. (Ed.): Wichtl – Teedrogen und Phytopharmaka. 6th Edition, Wissenschaftliche Verlagsgesellschaft Stuttgart, 2016. ISBN 978-3-8047-3068-7. — Monographs on drug quality and preparations; information on recommended ethanol contents for each medicinal drug.
- Bühring U.: Praxis-Lehrbuch der modernen Heilpflanzenkunde. Sonntag Verlag Stuttgart, 2005. ISBN 978-3-8304-5300-5. — Practice-oriented standard work of German-language herbal medicine with a detailed chapter on tincture production including fresh plant tinctures.
- Reichling J., Gachnian-Mirtscheva R., Frater-Schröder M. et al.: Heilpflanzenkunde für die Veterinärpraxis. Springer-Verlag Berlin Heidelberg, 2008. ISBN 978-3-540-35695-8. — Contains precise representation of extraction physics (equilibrium concentration, percolation) and ethanol dependence of active compound groups; verified via SpringerLink.
The information on ethanol concentrations and drug-menstruum ratios corresponds to generally accepted values from pharmacognosy and pharmaceutical technology. For therapeutic applications, the monographs of the Ph. Eur. and DAB are recommended as the binding reference.
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