Read the important steps of filtering and winterizing wax in hemp extraction and how extraktLAB's DrainDroyd is the best system for the task. One of the most critical steps in terms of making a clean cannabis product is CBD winterization. If you’ve ever wondered what that means, click to learn more!
What You Should Know About Filtration, Winterizing Wax and CBD Extraction
After grinding, decarboxylating and extracting hemp the next important step is to filter and winterizing wax. In this article, we explain why this step is crucial to supercritical CO2 extraction.
Grow, harvest, test, grind, decarboxylate, test again, extract… What’s next? Depending on your extraction method of choice, it is very likely that the next step in creating your hemp concentrate will involve winterizing wax and filtering your mixture to begin the distillation process.
Because the crude oil that is created with methods like supercritical CO2 extraction will often contain waxes and lipids, it becomes important to remove them to create a quality final product for the consumer.
So, let’s take a look at this important process and why supercritical CO2 extraction benefits from it.
What is Winterization?
Winterization is the process of removing fats and waxes from the hemp extract. The process involves dissolving the CBD oil coming out of the CO2 extractor in food grade ethanol and subsequently chilling the ethanol oil mixture down to -20 degrees Celsius. The fats and waxes are less soluble at those temperatures and they will precipitate while the cannabinoids remain in solution. The fats and waxes are then filtered before solvent removal.
Why Winterizing Wax is Important
Because extraction will also take out plant waxes and fats with the desired cannabinoids, winterizing wax is critical to create a product that is desirable to the end user.
Winterizing wax and then filtering oil is important to remove the fats and waxes that would otherwise cause flavor and consistency issues. In vape products, for example, fats and waxes can cause a harsh flavor and can even cause irritation of the throat as well. This can all be mitigated by winterizing wax and filtering it out.
By winterizing wax, you solidify the plant fats and waxes at frigid cold temperatures while the desired components remain in a liquid form. This allows for a vacuum filtration method to be used that pulls the oil through a filtration medium that traps the waxes, fats and chlorophylls while allowing the desired cannabinoids and terpenes to be collected. This results in a higher quality product that is desirable and profitable to the end customer.
Why Winterize and Filter Your Oil?
Depending on the product that is being created, remaining waxes and lipids can cause a number of issues for both producers and consumers:
For the producer, remaining waxes and lipids can dilute product potency, and cause a lesser quality distillate overall. Quality and clarity of a hemp extract often go hand-in-hand, and remaining waxes can cause a final distillate to be cloudy or of undesired consistency – not the result a producer wants to see after all the hard work.
For the consumer, waxes and lipids left in an extract can result in a shotty product as well. For example, smokeable hemp extracts or “dabs” as they are often called can come in the form of what is called “shatter” given its translucent clarity and breakable consistency similar to glass.
Both clarity and consistency mean quality shatter and a happy customer, but when residual waxes are left in the product it can cause what is called nucleation making that clear, brittle shatter turn into a soft, sticky opaque consistency.
Furthermore, fats and waxes left in any hemp concentrate can be harsh or have undesirable tastes when smoked or vaporized. Because of this, it is very important to properly winterize and filter those remaining waxes and lipids. And, there are many methods to do this.
As a proud proponent of supercritical CO2 extraction, extraktLAB does not use denatured ethanol for an extraction method for a number of reasons. However, a common method of winterizing wax involves the use of ethanol. So, we often face a recurring question in the dewaxing process.
Why Use CO2 Extraction When You Use Ethanol for Winterization?
Though it is undoubtedly the cleaner extraction solvent, biomass, fatty acids, waxes and resins can be co-extracted along with the cannabidiol and other cannabinoids when CO2 is used to extract hemp. The amount that is extracted depends on the pressure of the CO2 extraction.
In general, the higher the pressure and longer the runtime, the more acids and waxes will be extracted. Low pressure CO2 extraction methods, known as subcritical CO2 extraction, produce extracts that require very little post processing.
Many companies actually skip the winterization process depending on what they are using the oils for. The trade-off for lowering the extraction pressure to subcritical is that the run time increases greatly. The flow rate must be increased to compensate for the lower run time. In the case of our extraction equipment, the flow rate increases as the pressure goes down so those customers desiring runs of critical methods are able to do so with significant efficiency.
In the case of supercritical CO2 extraction, winterizing wax is likely going to be needed. The cannabinoids and CBD oils that remain in the solution are then introduced into a falling film evaporator. The ethanol is removed from the solution and may be recycled once it has been re-conditioned and tested for reuse. The amount of ethanol that is used in the winterization process is very small compared to the amount of ethanol that is used during an ethanol extraction.
For example, one gallon of ethanol is required to fluidize one pound of hemp for ethanol extraction. 1000 lb of hemp by extension requires 1000 gallons of ethanol. In contrast, 1000 lb of hemp at 10% cannabinoid will produce approximately 100 lbs of CBD oil. 100 lb of CBD oil – Approximately 30 gallons Of CBD oil, so 180 gallons of ethanol is needed to winterize 30 gallons of CBD oil.
What is CBD winterization?
There are many steps to processing hemp into a consumer-level product. One of the most critical, in terms of making a clean product, is winterization. No, this isn’t what your dad does to the lawnmower every fall. Winterization is a process that removes undesirable elements extracted from hemp, for example, fats, waxes, and lipids leaving behind clean, consumable CBD oil. Without CBD winterization, these unwanted materials would cause the final product to be cloudy, darker, and have an unpleasant taste.
What steps come before the winterization of oil?
The winterization process starts with raw extract straight from our CO2 machine (see photo below). This CBD crude oil contains all the essential parts of the hemp plant except for the actual plant material itself. CBD, minor cannabinoids, terpenes, fats, waxes, and lipids are all part of this viscous liquid. Crude oil extracted from a CO2 machine will have an attractive, light color to it, especially compared to alcohol extracted oil, which will have a dark, sludge-like appearance.
What is CBD Winterization?
The CBD crude oil is combined with 200 proof alcohol and stirred vigorously until completely mixed. The alcohol is used to thin the crude oil out, as the desirable parts of crude will go into solution with the alcohol while the undesirable parts will coagulate and freeze allowing them to be filtered out. The mixture is then placed in a deep freezer at below-zero temperatures. Once it has time to freeze it looks cloudy and is ready for filtration. The next step is to place the mixture in vessels that use paper filters to remove the frozen fats, waxes and lipids. The actual CBD oil remains with the alcohol solution and passes through the filter while the frozen undesirable parts are caught by it. The photo below shows what a filter will look like after the solution passes through it. When properly winterized, the filters will catch all of the frozen plant waxes from the oil, leaving them sitting on top. Once the pass is complete, the filters and waxes are discarded. The clean oil flows through the filter into a collection vessel where it is refrozen for more passes. We winterize multiple times just to make sure that our oil is 100 percent clean!
So wait, even though the winterized oil is CO2 extracted, it will still contain alcohol?
Nope! The alcohol is just used to thin the CBD oil in order to properly filter it. Once it’s been filtered and the undesirable elements have been removed, it’s time to remove the alcohol. This is done with a piece of equipment called a rotary evaporator (rotovap). This is CEO Craig Henderson, who started refining hemp from the garage of his home, using a rotovap in the early days of Extract Labs. This bad boy is an efficient way to quickly distill the alcohol out of the solution. The bulb spins in a hot water bath while the system is under vacuum, allowing the alcohol to evaporate out while leaving the winterized oil spinning in the bulb. The alcohol vapors then travel up to the chiller coils where they condense into a liquid and drip down for collection. The alcohol is then recycled into our process. Once the rotovap is done with a work order, the spinning bulb will contain only clean winterized CBD oil. The winterized CBD is then ready to move on to the next phase of the process. From here, the winterized oil will be formulated into tinctures or it will move to our distillation department for further refinement.