Tincture Ratios Explained (1:2, 1:5, Folk)
A tincture ratio states the weight of plant to the volume of menstruum: 1:5 is one gram of herb to five millilitres of liquid, 1:2 is one gram to two millilitres. The first number is always the herb, the second the solvent, and the ratio is written with the alcohol percentage after it, so that 1:5 in 45 percent is a complete description of a tincture and 1:2 in 95 percent another. A dried herb is made at 1:5 as the standard of the British Herbal Pharmacopoeia; a fresh plant at 1:2; a fluid extract at 1:1; and a potent low-dose plant at 1:10. The ratio fixes how much plant a millilitre carries and therefore what the dose in millilitres means.
What the numbers say
A 1:5 tincture carries 0.2 grams of dried herb in every millilitre. A dose of 5 millilitres represents a gram of the plant, and a day's dose of 15 millilitres represents 3 grams, which is the same quantity a person would take as an infusion of the dried herb. This is the conversion that lets the herbalist move between forms: the monograph dose of a plant in grams, divided by 0.2, is its dose in millilitres of a 1:5 tincture; divided by 0.5, its dose of a 1:2. The ratio is not a measure of quality, only of concentration, and a well-made 1:5 of a good herb outperforms a 1:2 of a stale one.
The 1:2 is the practitioner's strength in the Australian and British clinics, favoured by Mills and Bone because a smaller volume covers the day's dose, and the 1:1 fluid extract is the pharmacopoeial concentration, made by percolation rather than maceration, because maceration cannot dissolve a gram of plant in a millilitre of liquid. The 1:10 belongs to the plants that are dosed in drops: Lobelia, Lobelia inflata, Poke root, Phytolacca americana, and the old pharmacopoeia's Belladonna and Aconite, which are not made at home.
Fresh plant ratios
A fresh plant is mostly water, and the ratio counts that water as part of the plant, not the menstruum. Michael Moore's method, now general, is 1:2 in 95 percent alcohol for fresh material: 100 grams of fresh herb to 200 millilitres of spirit. The 70 to 90 grams of water the plant releases dilute the spirit to somewhere near 50 to 60 percent, which is enough to preserve the result and to hold the volatile constituents that drying loses. In dried-herb terms a fresh 1:2 is roughly a 1:5 to 1:6, and it is dosed as a 1:5 is. Fresh 1:1 in 95 percent is also used, and is closer to a dried 1:3.
Alcohol percentage by constituent
| Percent alcohol | Draws out | Plants |
|---|---|---|
| 25 | tannins, mucilage, minerals, most flavonoids | Marshmallow root, Althaea officinalis; Meadowsweet, Filipendula ulmaria; Raspberry leaf, Rubus idaeus |
| 45 | flavonoids, glycosides, most alkaloids, bitters | the general strength: Skullcap, Scutellaria lateriflora; Nettle, Urtica dioica; Elderflower, Sambucus nigra |
| 60 | essential oils, some alkaloids | Valerian, Valeriana officinalis; Ginger, Zingiber officinale; Peppermint, Mentha piperita |
| 90 | resins, oleoresins, essential oils | Myrrh, Commiphora myrrha; Calendula, Calendula officinalis; Propolis |
The percentage and the ratio are chosen together. A 1:5 in 25 percent of a resinous plant extracts almost nothing; a 1:5 in 90 percent of a mucilaginous root precipitates the mucilage into a useless gel. The British Herbal Pharmacopoeia of 1983 lists a ratio and a strength for each plant it covers, and those figures remain the reference in English-speaking practice.
The folk method against the ratios
The folk method, a jar filled with herb and covered with spirit, produces something between a 1:3 and a 1:8 depending on how the jar was packed and how much the dried plant swelled. It cannot be dosed by the conversion above, and it is not what a monograph means when it gives a dose in millilitres. It is a sound preparation for a mild plant used at home. For a plant with a narrow dose range, for a plant with a drug interaction, or for anything that is to be dispensed to another person, the weight-to-volume ratio is the method, because the dose then means something.
Ratios for other preparations
The same notation covers the other liquid extracts. A glycerite is made at 1:5 dried in 60 percent glycerin, or 1:2 fresh in pure glycerin. An acetum, a vinegar extract, is made at 1:5 in cider vinegar and dosed at a tablespoon rather than a teaspoon, since vinegar is a weak solvent. An infused oil for a salve is made at roughly 1:5 to 1:8 of dried herb to oil by weight. A syrup is described by its sugar to liquid ratio, 1:1 or 2:1, which speaks to preservation rather than strength.
Not medical advice.