From potent THC vapor pens to CBD tinctures, the distillation process is a key step in creating some of the most desired products in the industry. But how is it done? How is CBD extracted from the hemp plant, and can you make your own CBD-infused oil at home? Read our CBD extraction guide to find out.
How to Make High Quality CBD Distillate
Distillation is a science that has been used for thousands of years, but it’s now known as the final gateway to creating some of the purest forms of hemp and cannabis products. Extracting, isolating, separating, and distilling pure cannabinoids are among the top trends in the world of cannabis production.
Equipment and techniques for creating these pure products have developed almost exponentially within recent years. From potent THC distillate vapor pens to CBD tinctures, the distillation process is a key step in creating some of the most desired products in the industry.
The steps before distillation
Before we walk through the distillation process, we need to look at the steps that get us to CBD oils that can be distilled. In order to get those desired cannabinoids, they first need to be extracted from the plant.
The extraction of hemp or cannabis typically involves the following steps:
- Drying the hemp or cannabis to 5-15 percent water content.
- Shucking the flower from the stems.
- Grinding of the flower to 2-300 microns to enable more efficient extraction.
- Decarboxylating or removing carbon dioxide from the cannabinoids to make them neutral and activating the cannabinoids.
- Collecting of terpenes for later use in formulation.
- Supercritical CO2 extraction .
- Winterization and filtration of the extracts to remove waxes and fats from the extract.
- Removing any ethanol solvent from the winterized oil using a thin film distillation apparatus.
Once these steps have been accomplished, then the winterized CBD oil is ready for distillation.
What is CBD distillate?
Very simply, distillation is the separation of molecules through selective boiling and condensation. An example of this is practiced in the world of alcohol distilleries. In order to create a higher alcohol content in spirits like vodka or whiskey, a distillery needs to use distillation to separate other materials from alcohol. But how is it done?
Alcohol has a lower boiling point than water and is therefore more volatile, causing it to evaporate at a lower boiling point. Because of this, a distillery can use a set temperature (roughly 173 degrees Fahrenheit) to boil off the alcohol in a solution causing it to evaporate. After evaporation, the alcohol will collect in a chilled condensation column where it will be more potent and free of water and other unwanted residuals.
Now, let’s apply this science to cannabis concentrates.
Compounds separated through distillation
When we talk about distilling cannabis products, we have to consider what components we are separating from the plant itself. These can be broken down into a few categories:
Cannabinoids: These are the naturally occurring compounds in the cannabis plant that give it its unique profile and react with the body’s natural cannabinoid receptors. These include tetrahydrocannabinol (THC), cannabidiol (CBD), cannabigerol (CBG) and others.
Terpenes: Naturally occurring compounds derived from repeat units of isoprene. These compounds are found in cannabis, hemp, hops and other plants as well. Well known terpenes include limonene (lemons), pinene (pine trees), linalool (lavender), among many others. Terpenes are thought to contribute to the health effects of the cannabis plant although much research has yet to be completed.
Flavonoids: These lesser mentioned compounds are phytonutrients found in virtually all plants and are partially responsible for color, aroma, and flavor. While these aren’t quite as prevalent in the cannabis plant, they may play a role in the potential health benefits found in cannabis.
Fats and waxes : Class of hydrophobic high molecular weight resins that are produced by plants and may be extracted.
How to extract CBD
Now that we’ve looked at the scientific basics and the compounds we can acquire, let’s dive into the cannabis distillation process.
Take CBD for example. CBD’s boiling point is roughly 320-356 degrees Fahrenheit. A typical solvent used for extraction is ethanol, which has a boiling point of 173 degrees Fahrenheit. Because the ethanol has a lower boiling point than the CBD, it will evaporate first and collect in a chilled condenser separating it from the desirable plant components.
So, the leftover product should be nothing but pure CBD, right? Well, not quite. The product may still contain chlorophyll and terpenes. How do you remove these to make a nice, clear distillate? You use wiped film distillation equipment.
Common distillation equipment
Short path distillation
A common class that covers a range of distillation equipment is referred to as “short path” but really isn’t due to the fact that the condenser is external to the evaporator. More accurately termed “fractional distillation,” this kind of equipment is typically constructed of glass and is used for solvent removal and distillation on a laboratory scale due to its relative simplicity, small footprint, and lower price tag.
Thin film distillation
When it comes to cannabis products, it’s very important to incorporate thin film distillation . This will create a thin film of oil across an evaporative surface. This, coupled with vacuum pressure to lower boiling temperatures, ensures that the evaporated components (cannabinoids in this case) aren’t in prolonged contact with the heat source reducing the risk of damaging them. There are several variations of equipment capable of doing this.
Likely the most commonly used equipment for solvent removal, rotary evaporators, or roto-vaps, utilize a rotating round bottomed flask to create a thin film. The heat source is reliant on a warm bath that the round bottom flask rests in. This is particularly good solvent removal at a small scale, but is discontinuous. This means it’s generally not a scalable technology if you have a lot of solvent to remove. They aren’t typically compliant with special fire hazard occupancy rules.
Falling film distillation
Similar to rotary evaporators, falling film distillation equipment is great for solvent removal and uses lower viscosity oils. This occurs by allowing the oil to drain down the inside of a heated column. This continuously creates a thin film on an evaporative surface before being collected on a chilled condenser.
Wiped film distillation
As a product becomes more refined, its viscosity increases. This means that typical methods of distillation like rotary evaporation or falling film evaporation aren’t as effective. Wiped film distillation machines use mechanical wipers that spread a thin layer of oil across a heated evaporative surface allowing the cannabinoids to evaporate and recollect on a chilled condenser that is only a short distance away. This is known as short path distillation. At this point, the final product could contain numbers of cannabinoids as high as 90 percent or more and should also be a nice golden color.
Why do distillates matter?
So, why go through all the trouble to grind, decarboxylate, extract, winterize, and distill a cannabis product? It all comes down to the final product.
On the product level, a distillate has the huge benefit of purifying key components of the cannabis plant that can be re-introduced with particularity. Through decarboxylation, extraction and distillation, desired components like CBD, THC, terpenes, and flavonoids become the basis of many different products including tinctures, edibles, topicals, and non-food supplements.
Typically, manufacturers will also sell bulk oil such as full spectrum distillate, broad spectrum, or crystal CBD isolates. Manufacturers use these to produce consumer products that are known in the market as full spectrum or broad-spectrum products.
- Full spectrum: These formulations contain cannabis plant components, cannabinoids as provided by the plant, and a full spectrum of terpenes. For CBD products, the THC is limited. Federal regulations only allow a percentage less than 0.3 percent of THC .
- Broad spectrum: These formulations contain CBD and a full spectrum of terpenes but not THC. However, they aren’t considered “THC-free” but are considered to be “THC non-detect” with the analytical method of choice. For example, THC isn’t detectable at 300 nm. Minor cannabinoids may or may not be present in broad spectrum oils depending on the plant. These formulations may be beneficial for consumers looking for the entourage effect , a synergistic effect of terpenes and cannabinoids that can amplify the beneficial effects of each compound without concern for THC content.
All of these formulations are reliant on a producer’s ability to purify each of the plant components through distillation. This way, any select combination of cannabinoids and terpenes can be created for a distinctive product tailored to the needs of the consumer. From the standpoint of a manufacturer, this is a crucial part of any cannabis market.
The future of cannabis products
Not long ago, the future of cannabis was on the horizon in the form of distillates, now the future is here. The ability to extract, separate, and reintroduce specific, purified cannabis components has opened a world of product formulation. Because of distillation, the world of cannabis has experienced these undeniable benefits:
- Consistently pure cannabis oils.
- The ability to create nearly endless product formulations.
- The opportunity to explore numerous health benefits of specific cannabis compounds.
Jon Thompson, PhD, is a separations scientist and CEO of extraktLAB, an accredited engineering company for the CBD, hemp and cannabis industries.
CBD Extraction: CO2, Steam Distillation, and More
We’d like to thank CBDfx and Natural Hemp Solutions for supplying us with images of the processes used in their labs.
Cannabidiol, or CBD for short, is an organic compound that is found in the cannabis plant, with the flowers of the hemp plant being the richest source. And in order for CBD to be added to a wide array of consumer products—think CBD oil, lotions, topicals, or CBD vape juice—the first step that manufacturers need to take is to extract it from the plant.
This guide will present the various CBD extraction methods, essentially explaining how full-spectrum CBD oil is obtained from the CBD strains of cannabis. Some of these methods have been used in various industries for decades or even centuries, far before CBD oil was even a thing. Examples include essential oil extraction, decaffeination (and caffeine extraction) of coffee beans, and even beer production. In all cases, the idea is the same: how to extract a valuable resource out of plant material.
If you are interested in the ins and outs of CBD extraction from cannabis strains high in CBD, here’s a breakdown of the most commonly used CBD methods.
Supercritical CO2 extraction
The word “supercritical” sounds real fancy, but it is actually a term that’s very commonly used in chemistry. Simply put, a substance in its supercritical state possesses characteristics of both a gas and a liquid.
When supercritical CO2 is used in CBD extraction, its gas properties allow it to effuse through all plant matter, while its liquid properties allow it to extract compounds efficiently. The exact process varies, and some labs start the extraction with liquid CO2 while others start with CO2 in gas form. In both cases, manufacturers add CO2 in a chamber that includes plant material and use the exact amounts of pressure and temperature needed for CO2 to reach its supercritical state. At this point, and with the help of some additional heat, CO2 acts as a solvent and causes the plant material to separate, carrying with it all the essential compounds. Once done, CO2 is separated from the organic compounds, and manufacturers are left with full-spectrum CBD oil.
While it requires qualified personnel and there are higher costs associated with the equipment needed for supercritical CO2 extraction, it is by far the most efficient and quickest method to extract CBD. It is also environmentally friendly due to the limited amount of emissions, and safer than extractions that use certain solvents as CO2 is “generally regarded as safe” by the FDA.
- The most efficient method
- CO2 is regarded as generally safe
- Quick (once everything is in place)
- Environmentally safe
- Expensive (equipment costs)
- Needs qualified personnel
Steam distillation is a centuries-old process that’s commonly used to distill alcohol as well as extract essential oils from organics. The process is much less complicated than CO2 CBD extraction. First, plant matter is introduced in a distillation tank. With the use of water and heat, the produced steam carries oils to the top of the tank, and it is then passed through a condenser, resulting in a mix of water and oil. The mix then goes through further distillation to separate water and oil, and the result is full-spectrum CBD oil.
While this CBD extraction process is much simpler, there are some downfalls. It is more prone to error, much less efficient, and may potentially damage part of the essential oil profile of the plant. Due to these reasons, steam distillation is very rarely used to extract CBD nowadays, but many labs still use some type of distillation in the process of isolating CBD from full-spectrum oil.
- Relatively easy to perform
- Low cost
- Not very efficient
- Not consistent
- Resulting CBD oil is less potent
This method is also centuries old and is somewhat of a middle point between CO2 extraction and steam distillation when it comes to complexity and efficiency. It bears many similarities to CO2 extraction, albeit without the advanced methodology that’s behind the “supercritical” part.
In layman’s terms, this type of extraction involves mixing plant material with some type of solvent that will carry the essential oils given the right conditions and enough time. Some of the most popular natural solvents are alcohol (ethanol) and natural plant oils (including olive oil), with alcohol being much more efficient in dissolving the plant’s compounds. But due to the higher cost associated with ethanol, many manufacturers choose to go with synthetic solvents (hydrocarbons like butane or hexane), which may end up in lower quality, or even CBD oil that’s unfit for consumption if they’re not removed properly from the final product.
Solvent extraction is a delicate CBD extraction process and its pros and cons, as well as the consistency of the resulting oil, varies greatly depending on the solvent used. It can be more efficient than steam distillation if performed properly, but it carries a lot of risk and most labs choose CO2 extraction if they can afford it.
- More efficient than steam distillation
- Can be performed with natural oils
- Relatively safe if natural oils are used
- Varied results in final product
- Not as efficient as CO2 extraction
- Synthetic solvents are dangerous to handle
- Synthetic solvents need to be completely removed from final product
How to extract CBD at home
At this point, you may be wondering if there’s any way you can extract CBD at the comfort of your own home. The short answer is “yes”, but it really depends on how willing you are to do further research. The following is not going to be a real step-by-step guide, but it can serve as a starting point and give you some basic guidelines.
Olive oil extraction
Possibly the simplest way to extract CBD oil, as it only requires some CBD-rich bud, olive oil, and some basic kitchen equipment to ensure a steady supply of heat. If you’ve ever made cannabutter, then technically you have already utilized this method before. The only difference in this case, is that you are using hemp and olive oil—but olive oil can easily be swapped out for the oil or butter of your choice. This includes regular butter, coconut oil, hempseed oil, etc.
The first step for olive oil extraction is decarboxylation, i.e. activation of the compounds of plant material with the use of heat (there’s more info in the following section). Trimmed hemp flower in an oven tray heated between 240 and 280°F (115-135°C) for up to an hour should do the trick. Once this step is taken care of, the resulting activated cannabis is mixed with olive oil and heated at low temperature (ideally in a double boiler) for around two hours. The only thing left to do at this point is to use a filter to strain the mixture and separate the oil from the plant material. The result: CBD-infused olive oil.
While this is the easiest and least risky way to extract CBD oil, it is certainly not the most efficient. As with most DIY projects, there’s always room for user error. But even if you do everything right, you are going to sacrifice a large part of the organic compounds of the plant and you will produce less potent oil than a lab would. For these reasons, extracting CBD at home is an interesting experiment, but if you want to reap all the benefits of CBD it is advisable to get it from a reputable source instead.
Activation and purification
While technically not steps of CBD extraction, activation of active organic compounds and purification of CBD oil are two processes that are very important in CBD production. The most common methods used for these purposes are decarboxylation and winterization.
The active organic compounds of the cannabis plant come in their acidic forms. In order to go from THCA and CBDA to THC and CBD, manufacturers need to apply heat and decarboxylate the compounds—that’s the lab equivalent to lighting up a joint. Heat removes a carbon molecule from the organic compounds and turns them into their active counterparts.
Decarboxylation may take place before or after the extraction, and the exact methodology followed is highly dependent on this choice. But it is an essential part of the CBD oil production process, as non-activated compounds have little to no effect on the user.
While not as essential as carboxylation, winterization is a very common process that ensures that the final product of the extraction is as pure as possible. Simply put, the process of winterization employs solvents (usually ethanol) and low temperatures to ensure that lipids and other impurities are removed from an oil extract. This takes place as one of the final steps before full spectrum oil is obtained.
Winterization is not always performed, but it is a very important process when the final product is intended to be vaped. Some terpenes and other compounds are also filtered out during this process, but many manufacturers choose to add terpenes to their CBD oil after winterization.
CBD extraction: the takeaway
These are the most commonly used CBD extraction methods and, as expected, each comes with its own advantages and disadvantages. The main takeaway from this guide should be that the reason you may have seen “supercritical CO2 extraction” in ads and promotions is not just that it sounds cool (although it does!) Simply put, CO2 extraction is by far the cleanest and most efficient CBD extraction method—and a no-brainer for any lab that can actually afford it.
This doesn’t mean that all CO2-extracted CBD products are better by definition. But if a lab invests in the equipment that’s required for the most technically demanding extraction method, chances are that they know what they are doing. When in doubt, check lab tests, and always choose third-party tested CBD products from reputable sources.