Reply To: Herbal Therapeutics
Hi Nanette,
Great questions here.
For most/all of the formulas in the Therapeutics section we use a weight to volume amount of 1:3 so one part plant to 3 parts alcohol (or whatever menstruum is used).
The 90% is referring to the strength of the alcohol, so in this situation the 5 mL of calendula tincture in the mouthwash formula would be a 1:3 (so within that 5 mL of tincture there would be about 1.7 grams of calendula) made of 90% (not 45% in this case). 90% strength is used to extract resinous compound from plants or tree resins (for example). In the case of calendula a 90% tincture contains the usual vulnerary, anti-viral, and anti-bacterial compounds but it would also contain anti-fungal compounds. In other cases there are plants that only need 25%, 30% or 40% strength, 45% isn’t always needed.
If you need to add more alcohol/menstruum to a maceration in order to cover the plant material, I would recommend adding it by the volume that would increase the ratio by one each time until the plant matter is covered and keep track of that. For example you are making a 1:2 of calendula tincture, starting with 10g calendula and 20mL of alcohol/menstruum and unable to cover the plant material for this. Add 10mL of alcohol at a time until it does cover the plant material and record how much you added. You can adjust you dose from this. For example, say you had to add another 30 mL of alcohol/menstruum that would total 10g calendula and 50mL of alcohol/menstruum, making it a 1:5. If the monograph says to use 2mL of 1:3 2x/day then this would now be 3.3 mL (or close to that) 2x/day.
A trick that I find really helpful to get plant material covered more easily is to blend up your plant with the alcohol/menstruum then press it down in the jar and check it in 12-24 hours to see if you need to add more.
I hope this helps a bit, it can take some practice making and calculating but when it clicks, it sticks. Please don’t hesitate to ask for more clarity if you need it!
Best,
Benna