Determining Herbal Concentrations
Making herbal medicine can be amazing and powerful, but sometimes a bit daunting. Fear not, you got this! In this post I want to guide you through understanding what dried herb equivalents are and the process of determining herbal concentrations. Although not a completely necessary step in medicine making if you are only providing for you or your family, but if you are a practitioner or sell your products it is essential. This is even more important when making supplements such as dried capsules because you want to know how much you are actually taking!
So why is it essential? Well, knowing the concentrations of the plants in your extracts allows you to create consistent batches. That means the medicinal properties in your extracts will be present every single time you make them and in the same amounts! This is so important especially when you want to sell your blends.
There are two different ways to think about herbal concentrations. The first is to look at specific compounds in the plant and determine their concentrations. Take turmeric for example, the most prominent medicinal compound in turmeric is curcumin. Oftentimes when turmeric is tested it is done by determining the curcumin content within an extract.
However, this requires complex instrumentation and lots of expertise. Which brings me to the second and my personal favorite way to determine herbal concentrations, by looking at their dried herb equivalents! But what does dry herb equivalent mean? This means you are looking at the amount of plant material you used to make your extract. This is an easy and surefire way to create consistent extractions!
You do this by taking the ratio of plant material used to the amount of menstruum or solvent used. This is known as the herb to menstruum ratio; so if you are extracting in alcohol it would be the herb to alcohol ratio. Likewise, if you are using an oil it would be the herb to oil ratio for infusion.
There are two ways to create this ratio. You can weigh both your herb and menstruum to create a weight to weight (wt:wt) ratio or you can weigh your plant and measure the volume of your solvent to create a weight to volume (wt:v) ratio. In both cases the plant material is displayed first (ie. 1:2) and the menstruum second, in case you come across this nomenclature on a product or something!
I always formulate my extractions on a weight to weight basis because I find it easiest to translate between different solvents, but you do whatever you find the easiest! To determine the concentration of your extract all you have to do is divide the weight of your herb by the weight (or volume) of your menstruum. This will give you a percentage, to convert this into a ratio you can use the below chart!
herbal concentration=(herb wt./menstruum wt.)x 100 %
Basic weight to weight recipes for a 1 kg (roughly 1 L) batch.
percent
100.00%
20.00%
10.00%
8.00%
5.00%
2.00%
ratio
1:1
1:5
1:10
1:12.5
1:20
1:50
herb weight
1000 g
200 g
100 g
80 g
50 g
20 g
menstruum weight
1000 g
1000 g
1000 g
1000 g
1000 g
1000 g
One other thing to keep in mind is the density of your menstruum, this allows you to convert between weight and volume. Density is a measure of the weight of a set volume or how much a certain volume weighs. An easy way to wrap your head around density is to compare the weight of one cup of water and one cup of oil. The oil weighs less because it has a lower density!
A common unit for this is grams (g) per milliliter (mL), or in other words how much does one milliliter weigh! The density changes greatly depending on the solvent you use so the same volume may weigh completely different when comparing them. A great comparison would be alcohol, olive oil, and water. Alcohol is the least dense, ~0.79 g/mL, compared to olive oil, ~0.92 g/mL, and water, 1 g/mL.
To convert the weight of your menstruum to a volume simply divide the menstruum weight by the density.
To convert from a volume to a weight, multiply the volume by the density!
Below are the densities of some common solvents!
menstruum
vinegar
castor oil
grapeseed oil
coconut oil
squalane
40% alcohol (80 proof)
99% alcohol
density
1.053 g/mL
0.95 g/mL
0.915-0.925 g/mL
0.91-0.92 g/mL
0.81 g/mL
0.789 g/mL
0.7854 g/mL