Producing hemp oil at home is not a difficult task, however extracting the cannabidiol and preparing a high quality CBD oil from the Cannabis sativa plant is a lot more challenging and has to take into consideration the advantages and disadvantages of the various techniques that can be used for this purpose. The winterization of cannabis can play an important part.
Depending on the method used, the extraction procedure can leave unhealthy and unwanted by-products in the final oil. For this reason it’s necessary to go through an additional step that purifies the product and removes the waxes, lipids and residual solvents from the extraction. One of the most effective refinement procedures is winterization, which consists in soaking the extract in alcohol and freezing it in order to separate the residual products.
How winterization is done
Winterization, also known as alcohol wash, is done after the initial extraction procedure, which can use CO2, nitrogen, butane or other solvents. All these lead to the separation of cannabinoids and terpenes from the cannabis plant, and produce minimally unwanted substances, like plant waxes, fats and chlorophyll.
When CO2 is used for the initial step, the raw extract is placed in ethanol, then heated and finally frozen to filter out the undesirable by-products. The ethanol solution is warmed to approximately 120 degrees F, and it’s not frozen until all the solvent has evaporated. For proper winterization, the solution should be frozen for at least 24 hours at a minimum temperature of 32 degrees F, or for 48 hours at 13-5 degrees F.
After this step, the alcohol solution needs to be filtered for removing the waxes. The extraction and refinement steps can be repeated several times, until a pure oil is obtained. Now, please note that it’s possible for the final product, which is dark in color and has a maple syrup-like consistency, to have a green tint.
The green hues are given by chlorophyll, and can be removed through various methods, such as washing the extract with ethanol tincture, or exposing it to sunlight or UV radiation. While these procedures can remove the chlorophyll, in most cases a part of the cannabinoids are also destroyed; this happens at a slower rate, but it still affects the final concentration of cannabinoids.
Pluses and minuses of winterization of cannabis
When it comes to extracting cannabinoids from the Cannabis sativa plant, there is no perfect method, and all procedures have their drawbacks, whether these refer to by-products, costs or required time.
Winterization has its disadvantages, and the most important one is that the final CBD product contains fewer terpenes, so it’s less flavorful and aromatic than the oils obtained through other methods. On the other hand, the winterized CBD oil is more potent, so if you’re looking for a powerful product instead of an oil that smells good, then it’s surely a good idea to search for products obtained through this technique.
Then, some say that removing part of the terpenes also reduces the health benefits of CBD oil. It is believed that certain terpenes exert beneficial health effects, and that winterization could reduce the effectiveness of the oil; but if you think again that the final concentration of cannabidiol is higher, and that the beneficial effects of CBD have been already proved by several studies, then it’s preferable to search for an oil with more CBD than with a higher concentration of terpenes.