Breaking Down the Different Hemp CBD Extraction Methods
Hemp CBD is derived by extracting the oil from hemp plants. There are several different methods. Each process requires special equipment and materials. In this guide, we’ll discuss each hemp CBD extraction method.
What Part of the Hemp Plant is CBD Taken from?
While an entire hemp plant is usable, many manufacturers extract the CBD from only the stalks and stems. Hemp plants must contain 0.3% THC or less to be considered industrial hemp. This is the typical legal amount of THC permitted by most states that have legalized CBD and/or industrial hemp.
Supercritical CO2 Extraction
This is one of the most common methods for extracting CBD.
For this process, CO2 is pressurized and freezes from its liquid state. A specific temperature and pressure setting is used to pull the CBD from the hemp plant. Some of the additional phytochemicals from the plant also tag along. The CO2 can reach a temperature of -69 degrees Fahrenheit. Pressure is slowly increased to around 75 pounds per square inch (psi).
The hemp plants are placed in an extractor where the supercritical CO2 will pass through it. Once the solution is through the extractor, it passes to a separator. The collection container is where the CBD ends up and the CO2 passes through a condenser. This is where the CO2 goes back to a liquid state. It can be used more than once for extraction purposes.
Full-spectrum hemp CBD oil is often derived from this method.
Small Batch Subcritical CO2 Extraction
Subcritical extraction is essentially the same as supercritical CO2 extraction except the temperatures and pressures used are lower. This also means that the process takes longer. Subcritical extraction is ideal for making small batches of CBD.
In this process, chlorophyll is left behind. Some manufacturers prefer to have chlorophyll-free CBD oil. Ethanol and Solvent-Based Extraction
Ethanol extraction is a less expensive option. It is the most common of the solvent-based extraction methods. Ethanol is a grain alcohol product. Larger volumes of full-spectrum CBD can be extracted through this process.
Other common solvents include butane and alcohol.
The plant material sits in the ethanol. The liquid strips the terpenes and cannabinoids from the hemp plant.
From here, the liquid needs to be heated so that the solvent evaporates leaving behind the CBD oil Olive Oil Extraction
Olive oil extraction requires that you decarboxylate the hemp plant first. Decarboxylating occurs when the plant material is heated to 248 degrees Fahrenheit for one hour. The temperature must remain steady and the plant material must not be heated longer than 60 minutes.
Following decarboxylation, the hemp plant material is added to olive oil. The olive oil must be heated to 212 degrees Fahrenheit exactly. The hemp plant needs to be in the olive oil for at least 1 hour but not longer than 2 hours.
After the heating process is complete, the oil just needs to be strained. Then it is ready to use.
CBD oils made with this process or that contain olive oil are perishable. They do have a shelf life, and it is important to look for best by dates or inquire with the manufacturer if it is an olive oil-based CBD product.
Sonication is a rather new extraction method for hemp CBD. It is not used often due to the extremely high cost of the equipment. During this process, sound energy is used to agitate the plants
This process is typically used for making CBD crystalline and emulsification processes. Closing Thoughts
The extraction methods discussed here are the most commonly used in the hemp CBD industry. Each process contains specific steps to return a usable CBD oil in the end. Many manufacturers take the CBD oil through an additional refining or distillation process for further purification processes. If you prefer a specific type of extraction, seek out manufacturers that use the method you desire.