If you’ve ever wondered where CBD oil comes from and what manufacturing steps it undergoes before it hits the shelves, then you should find this page informative. Most people are aware CBD comes from cannabis, but how it gets into the products we buy is generally not well known.
There are a variety of extraction methods employed by the hemp industry to remove CBD oil from hemp plants. Why hemp and not marijuana? Whether CBD is extracted from hemp or marijuana, it remains identical on a molecular level. But industrial hemp doesn’t have the THC levels of marijuana, so it’s generally chosen for extracting CBD oil for commercial use.
“The CBD molecule and its own pharmacology that is associated are the exact same, whether or not it was obtained from hemp or from cannabis. CBD is CBD, wherever it had been initially derived from,” Jeremy Riggle, Ph.D, chief scientist at Mary's Medicinals
Methods of CBD Extraction
What is Extraction?
As it applies to chemical compounds this is the definition of extraction from the chemistry dictionary Chemicool:
Extractions are a way to separate a desired substance when it is mixed with others. The mixture is brought into contact with a solvent in which the substance of interest is soluble, but the other substances present are insoluble.
Extractions use two immiscible phases (these are phases that do not mix, like oil and water) to separate the substance from one phase into the other.
CO2 Extraction aka Supercritical Fluid Extraction (SFE)
CO2 extraction uses carbon dioxide to separate the CBD oil from the hemp leaves, seeds, and stems. It requires the proper extraction equipment along with qualified personnel to operate it. Supercritical fluid extraction consists of a CO2 gas supply, a pump, a thermostat-controlled heat element, a restrictor to maintain the high pressure in the column, and a detector. CO2 extraction is different from other types of extraction because there is a required temperature and pressure threshold needed to get to what is called the supercritical phase where the oils are caused to separate from the plant material.
CO2 extraction produces the highest CBD yields even though it requires machinery that is costly. It's safer for the producer and it’s efficient, producing CBD oil with high concentrations, extracting up to 92% CBD according to one scientific study cited in Science Direct.
Overall, CO2 produces highly concentrated CBD. It provides a healthier product than other extraction methods because it doesn’t leave behind neurotoxic residue.
CBD solvent extraction involves using chemicals like ethanol, butane, propane, isopropyl, or alcohol to remove the cannabinoids from hemp. It’s faster and cheaper than CO2 extraction, but it comes with risks due to the flammability of the solvents that are used.
Solvent extraction begins with the plant parts being placed in a container. The plants are soaked with the solvent of choice which then strips the cannabinoids from the plant material. Then the mix is left to evaporate. The evaporation process leaves behind the cannabinoids in a concentrated oil form.
The danger of using solvents that aren’t natural is that this method leaves behind some toxins from the solvents. Natural solvents like olive oil or ethanol are just as effective at extracting CBD oil, but remove the risk of toxic residue. The downside of using natural solvents is that some of the chlorophyll may also be extracted from the plant which results in a product that has an unsavory taste. If the CBD is sold in capsules that’s not an issue, but if it’s consumed in gummies, vaped, or used as a tincture it may be problematic.
One other problem with using natural solvents is they don’t evaporate well and the result is a product with a lower concentration of CBD. In the case of using olive oil as a solvent the product is perishable and storage guidelines must be followed.
Steam distillation has been used for centuries to capture aromatic compounds like essential oils. It’s basically a separation process that isolates temperature sensitive materials. In steam distillation, steam causes CBD to separate from the hemp plant. This method involves a boiler, a distillation tank, a condenser, water outlets, and a collection flask for the CBD.“In practice, the process uses water and/or steam as extracting agent to vaporize or liberate the volatile compounds from the raw material.” Science Direct
During steam distillation water is heated up causing steam to travel upwards through the plant material in the tank. Why is steam used? Using steam to heat the mixture ensures that the temperature of the compounds does not exceed 100 degrees. The collected vapor is then condensed, and the resulting fluid consists of a layer of water and a layer of the cannabidiol compound. They are then physically separated by decanting or the use of a separation flask.
While steam distillation is relatively safe, if not monitored there is a risk of too high temperature damaging the CBD. It also produces a lower quality CBD with inconsistencies. The flip side is steam distillation is cheap and no toxic residue is left behind.
What Happens After the CBD is Extracted?
Regardless of the extraction method used, the resulting CBD oil is full-spectrum. This means that other cannabinoids besides CBD remain in the oil, these include CBDA, CBDV, and possibly THC. If the original plant the CBD is extracted from is hemp then the amount of THC will be less than 0.3% which means its legal in any state.
Besides understanding the different methods of extracting CBD from hemp, you’ll want to learn about the differences between full-spectrum CBD, broad-spectrum CBD, and CBD isolate which is another topic we cover here.