Ever wonder why some concentrates like distillate and shatter have a beautiful, clear amber colour? Why do some cannabis products such as tinctures and budder, have a murky, forest-green colour?
The secret lies in a refinement process known as “winterization.” It doesn’t have anything to do with the winter, but extreme cold is definitely one of the primary elements involved.
Winterization is an important step in the production of CBD Oil. It refers to the step involved in the removal of waxes and fats from the crude cannabis extract to leave a pure, aesthetically pleasing product.
Want to clarify your concentrates and have them be a beautiful, translucent colour?
Stay with us we as explore the winterization process, why you should do it, and when you shouldn’t.
What is Winterization?
When manufacturing CBD Oil, unwanted compounds found in cannabis such as the plant’s lipids (fats) and waxes require separation for the pure CBD compound to be extracted.
Scientifically speaking, winterization is a refinement technique for oil that uses solvents and cold temperatures (sub-zero degree Celsius) to separate lipids and other compounds from oils.
This process utilizes the difference in phase transition points of different compounds (i.Melting point, boiling point etc.) to isolate specific compounds from an overall mixture.
With CBD oils, the process typically involves dissolving a non-polar cannabis oil extract in a slightly polar solvent such as ethanol and then freezing the mixture at a low temperature to chill.
The temperature shift means that compounds with higher melting points such as fats/waxes can precipitate out from the solvent and isolated by filtration. Once separated, the pure liquid oil extract is left behind.
When Would you want to Winterize Oil?
Cannabis winterization is important in creating a highly purified extract without a strong, vegetal flavour. When it comes to winterizing cannabis, there are several reasons why you would want to remove lipids and waxes from the final product.
- Fats can cause the final distillate to be less transparent, causing the oil to appear dark and murky.
- The high content of waxes and fats increase the harshness and biter taste that CBD oil has when unwinterized.
- Fats dilute the cannabinoid concentration, lowering overall efficacy and purity.
When used in products such as vape pens, fats can burn on the coil and give a burnt taste to the overall mixture.
When You Wouldn’t want to Winterize Oil
Winterization also has some disadvantages that also need to be considered when deciding on the composition of the final product.
The final CBD extract will contain fewer terpenes. Terpenes are organic compounds primarily responsible for aroma, taste and some therapeutic effects that are found in cannabis.
Whilst they are not identical to fats, their organic structure does mean that there is a high chance that a percentage of terpenes can also precipitate at low temperatures and ultimately extracted from the final product.
The removal of terpenes results in a product that can be less aromatic and flavorful than unwinterized oils.
Terpenes have been said to provide additional health benefits that can be lost from the CBD oil.
Additionally, if you don’t have the proper equipment and safety procedures in place; winterization can be a dangerous process.
For example, butane honey oil (BHO) is an extract made from through butane as a solvent. Using butane for cannabis extraction requires specific knowledge and extra safety measures.
BHO winterization involves removing the butane along with the undesirable fats and waxes to produce a visually appealing concentrate. Extreme care must be taken – butane is highly flammable, much more so than other commonly used solvents such as ethanol.
In this process, it’s important that all the butane is removed before attempting to expose the mixture to cold temperatures. If proper safety procedures are not followed, butane gas can subsequently leak and produce disastrous results.
How to Winterize CBD Oil: A Recipe
The first step of extraction separates the cannabinoids and terpenes from the cannabis plant.
Depending on the method used (Cold Ethanol Extraction, CO2 extraction or BHO extraction), this initial separation will also produce a specific amount of unwanted waxes and fats in the cannabis extract.
Winterization involves dissolving this “raw” extract in a solvent such as ethanol, which is then heated to allow the solvent to evaporate. Using ethanol, a temperature of around 78oC will suffice. Once fully evaporated, the solution needs to be frozen for between 24-48 hours below -20oC.
At cold temperatures, compounds in the mixture with a higher melting point, specifically the unwanted fats and waxes, will precipitate from solution.
After this step, the resulting alcohol solution needs to be filtered to remove the precipitate. A typical method can use vacuum filtration using a filter paper to extract the solution, leaving behind the resulting filter ‘cake’ of unwanted material.
The extraction and refinement can be repeated several times until an oil of desired purity is obtained.
Winterizing Cannabis for CBD Oil – Cannabis Winterization
Now that you know what the winterization process is and how to do it, it’s time to take matters into your own hands and start refining your own extracts!
At the same time, it’s important to keep in mind whether or not your concentrate will benefit from winterization and that you have the proper equipment and safety precautions in place.