In this method, CO₂ is manipulated to enter a supercritical state. With characteristics of both a gas and a liquid, it’s pumped through raw plant material under controlled conditions, stripping away essential terpenes and cannabinoids without damaging them.
Keep reading to find out how to extract CBD, and which method produces the highest-quality CBD oil. While they all harness the power of CBD, they don’t all achieve the same degree of purity.
How does one make CBD extracts without using a solvent? Simply enough, you just have to apply heat, pressure, or a bit of friction to hemp flowers and leaves. How do you do that, you wonder? Well, if you freeze hemp flowers, you can shake the small trichomes loose and gather them together. These trichomes, as you might know, contain the full spectrum of cannabinoids and terpenes found in the hemp plant.
Cons of solvent extraction
• Little control over the final extract
• Weak and unreliable CBD content compared to more professional methods
• Not suitable for commercial sale
Below, you will find a breakdown of some of the most common extraction techniques used, including their main pros and cons.
CO₂ extraction has significant advantages over other methods of producing CBD oil. First, you can pump supercritical CO₂ through hemp in such a way that it selectively picks up the cannabinoids and other compounds, leaving everything else behind.
• Working with solvents can cause injury if not used correctly, they are highly flammable
• The oil can remain contaminated with solvent, which is dangerous for the end-user
• Higher temperatures risk destroying some essential terpenes and other smaller compounds
Other varieties and planting strategies are used to grow hemp for hemp seed oil. Then, within the hemp grain sector, seeds can be processed for flour, hemp food supplements, and then onwards to a thousand uses within the food sector. Then there is the hemp hurd and bast fibre which has a multitude of uses. A number of separate possible revenue streams from the same plant; however in this article we focus mainly hemp grown for CBD oil extraction.
The other main types of industrial hemp crop are tall single stem hemp plants close-planted for seed / dual purpose uses. This type can have CBD oil extraction from the leaves, buds and flowers, but also can have hemp seed oil extracted from the seeds. It is not a simple process to optimise both the CBD oil yield and hemp seed yield.
Hemp Harvest Timing
Hemp cultivation areas are growing fast around the world. Hemp is an extremely useful and versatile crop; parts of, or the whole crop, can be processed into a number of highly useful products.
High value industrial hemp crops for CBD oil extraction from the leaf / flower / bud grown mainly as tree like hemp plants. Harvesting this form of industrial hemp in a whole crop method with forage choppers produces a type of wet woody biomass with leaf and flower in the mix.
Field scale production of high % CBD oil hemp plants using low THC strains is rapidly growing across the USA and Europe due to the new worldwide demand for CBD oil and the recent changes in regulation.
Hemp CBD varieties have not been well-validated for Nebraska but possibilities may include ‘Abocus’, ‘Autopilot’, ‘Boax’, Cherry Wine, Cherry Blossom, Cobbler, and Sweetgrass for high pharmaceutical-grade CBD yield but having less than 0.3% THC.. High CBD varieties are generally grown only as female plants, as the combination of male and female plants leads to seed production and decreased CBD yield. Breeders continue to improve the processes for creating stable feminized seed. Farmers need to be wary of the source of their feminized seed stock and to check test results for validation of feminized seed.
Farmers need to know state regulations for testing hemp for CBD and THC. The Nebraska Department of Agriculture (NDA) regulations for industrial hemp production have been approved by USDA. Plant sampling by NDA staff to test for THC needs to be within 15 days before the date of harvest with the grower present during sampling. If the THC level is >0.3% by dry weight, the crop will not meet the legal definition of industrial hemp and need to be destroyed. Again, THC is expected to increase with stressful growing conditions.
University of Nebraska-Lincoln Extension information typically is based on the interpretation of research information from Nebraska or elsewhere in the Midwest. However, such information is not available for hemp production due to previous restrictions on research in the U.S. This publication relies heavily on research findings from Europe and Canada and learning from growers’ experiences. See more stories in this series at https://cropwatch.unl.edu/tags/hemp.
CBD-containing products marketed in the US range from cosmetics to chocolate bars to bottled water to pet treats, all with no regulation. The Food and Drug Administration warned marketers of CBD products against the use of non-validated health claims to sell their products. In June 2019 the FDA approved the first CBD-based drug, called Epidiolex, to treat seizures caused by extreme types of epilepsy. The efficacy of CBD for treatment of chronic pain, neuro-inflammation, anxiety, addiction, and anti-psychotic effects has not been well-validated by clinical research.
Market information is too weak for prediction or advice but information is improving such as with a USDA ERS Feb 2020 report.