How is CBD Oil Extracted from Hemp?
First off, what is Hemp?
Botanically speaking, hemp is a type of Cannabis sativa (a species of the Cannabis genus) characterized by the presence of high quantities of Cannabidiol (CBD) — a phytocannabinoid that accounts for up to 40% of the plant’s extract with low-to-negligible amounts of THC (typically less than 0.3%).
Types of Cannabis sativa that exhibit higher quantities of THC are classified as simply as “cannabis”.
There are two other species of Cannabis; Indica and Ruderalis, which are both usually simply classified as Cannabis. However due to hemp’s strict classification being based upon the plant’s chemical constituents, technically species of Indica and Ruderalis can be considered Hemp as well.
Sounds confusing? Essentially, they are all species of the Cannabis genus, but the term “hemp” is used to specifically with regards to plants with less than 0.3% THC content.
This definition is due largely in part to the passing of the 2018 Farm Bill which defines hemp as the plant Cannabis sativa L. and any part of the plant with a delta-9 THC concentration of not more than 0.3% by dry weight.
So... What is CBD?
Cannabidiol, abbreviated to CBD, is a Cannabinoid. Cannabinoids are compounds found in cannabis and colloquially divided into “major” and “minor” cannabinoids.
The most notable major cannabinoids are the phyto-cannabinoid tetrahydrocannabinol (THC) (Delta9-THC or Delta8-THC), the primary psychoactive compound in cannabis. Cannabidiol (CBD) is the major cannabinoid.
But there are at least 144 different cannabinoids isolated from cannabis (at the latest count!) delivering varied effects to the human body. However, the two most prevalent and the two that the plant produces in the highest quantities are Cannabidiol (CBD) and Tetrahydrocannabinol (THC).
What part of the Hemp Plant does CBD come from?
So now that we know what CBD is, especially if we intend to extract this valuable cannabinoid, it will be helpful to understand where the CBD is produced on the plant.
Like most woody plants, hemp plants have a sometimes quite large stalk or stem that runs up the entire plant and it has branches like a tree branching out from the main stem. From these branches grow the archetypal fan-type leaves which spread out in odd numbers of 5, 7, and 9, and the colas or buds of the plant.
When we are processing the hemp plant, we can simplify its anatomy into these four categories: stalk, branches, leaves, and buds or colas.
Furthermore, when intending to extract and refine CBD from the hemp plant we are primarily only concerned with the Colas or buds, and the surrounding leaves or trim of the plants. All other plant materials are best to remove because they have little to no CBD and they make the extraction process more difficult and time consuming and less profitable.
On the Colas of the mature hemp plants are what appear to be tiny visible crystals or dew droplets. These are called Trichomes, and these are the glands in which the Cannabinoids like CBD and THC are produced by the plant.
How is CBD Extracted from Hemp?
The first stage of extraction begins at harvest; the removal of the stems and branches from the Colas and Leaves. This process is generally referred to as ‘bucking’ the plant.
After bucking the remaining branches, colas, and leaves are hung to dry.
Once mostly dried, the remaining branches, leaves, and stems are removed in a process called ‘trimming’. This trim, and not the flower, is what is most often extracted, simply because it still contains a considerable number of valuable cannabinoids but costs considerably less to purchase from the farmer then the higher quality buds and flowers.
Next, the plant’s Colas or buds are dried once more to achieve the proper moisture content for storage in a process called ‘curing’. At this point, the flowers are ready to be extracted or sold to consumers for smoking.
Most, but not all (think: Ice Water Hash and Rosin) cannabis and hemp concentrates need a solvent to first extract them from the plant. The most common solvents that are used in CBD extraction include alkanes such as Butane, Propane and Hexane, Carbon dioxide in its super-critical and sub-critical forms, and Ethanol (alcohol).
Each form of CBD extraction has its pros and cons, as well as their similarities.
All the above examples of solvent based extraction (or Solid Phase Extraction) follow the same basic process of submitting the biomass (CBD-rich hemp in this case) to the solvent which dissolves out the desired compounds from the plant material. After which, you have cannabinoid-saturated solvent that needs to be separated from the cannabinoids (and other desired compounds). This separation happens during evaporation during which the solvent is evaporated and removed from the solution, which then goes on to further refinement steps such as distillation and crystallization.
Along with the more commonly used solvents mentioned above, even coconut oil can be used to extract CBD — taking the place of one of the solvents we talked about above like ethanol or CO2. Coconut oil can be mixed with the plant material (biomass), or with an already-extracted crude from of hemp extract. It is then heated to dissolve the CBD into the coconut oil much like your sugar dissolves into your coffee. Then finally filtered of any residual plant matter.
Coconut oil or olive oil is a great method for small-scale home growers and cooks because it’s easy to do and leaves you with a healthy and edible oil to cook with, easy for dosing! However, vegetable oils oxidize quickly so your resulting CBD oil will need to be used quickly and/or stored in a temperature-controlled environment to ensure shelf-life and freshness.
How much CBD can I extract from one hemp plant?
This question is much more difficult to answer then one would think! This due to the many variables that come into play when attempting to calculate the amount of CBD you can extract from one plant. However, if we make some very lenient assumptions, we can make some very approximate guesses.
First, we’re going to assume your hemp biomass has been bucked, dried, trimmed, and cured properly prior to extraction. If this hasn’t occurred your yields will go down significantly.
Second, we’re going to assume this finished trim or flower contains 10% CBD.
Third, we are going to assume that each of your hemp plants produce 5 lbs. of this finished and cured material per plant.
Lastly, we are going to assume that the extraction facility that is processing your biomass knows what they’re doing! Possibly the biggest variable of all is human error.
- To produce 1 liter of CBD distillate (or oil) would require approximately 33-5 lbs. of good quality biomass; or about 7 large hemp plants.
- To produce 1 liter of CBD isolate would require approximately 38-40 lbs. of good quality biomass; or about 8 large hemp plants.
What is the difference between Crude extract and Distillate (oil)?
Lastly, we’d like to briefly define some basic, primary CBD extracts.
A common phrase you’ll often hear when talking about hemp is “CBD oil”. This refers to CBD distillate, a gold-to-amber colored viscous (thick) liquid which tends to be around 85-95% CBD and will crystallize or “sugar” when left at room temperature.
Other forms of CBD include isolate, which is a yellow-to-white powder or crystal that is of very high purity (98-100% pure CBD).
Another form is crude extract, which while less potent than either of the previous forms and ranging widely between 40-70% CBD, has a lot of other compounds (e.g. terpenes) extracted from the hemp which may also have health benefits. This form is usually a black and thick liquid and is almost exclusively used in edibles and topicals.
So, there you have it: the short version of how to extract CBD oil from the hemp plant. Of course, if you have any questions about CBD extraction or CBD extraction equipment please contact us.