The Complete Guide to CBD Extractions (CO2, Olive Oil, Solvents)
Why Is CBD Oil Popular?
CBD is one of the many compounds found in the cannabis plant. Science is just beginning to uncover the many medicinal benefits of CBD. Over the last few years, CBD or cannabidiol has become so popular that it is now being extracted, produced and manufactured into a wide range of products. These products include edibles, CBD oils, and even creams.
CBD oil is especially popular. It is used to treat a host of illnesses. CBD oil affects the endocannabinoid system (ECS) without providing users with a ‘high.’
In this article, we will look at the best ways to extract CBD from the cannabis plant but first, let’s find out what the substance is and why it is so coveted.
What Is CBD?
If you are reading this article, you probably know what THC is . It (delta-9 tetrahydrocannabinol) is the most psychoactive ingredient in cannabis, and until recently, it was by far the best-known.
THC is renowned for the mind-altering high it provides to users. In contrast, CBD is not psychoactive, but it does promote positive changes in the body.
The way CBD affects our body is quite different from the modus operandi of THC in the sense that it is not involved in direct stimulation of the CB1 and CB2 receptors. The major impact of CBD is on other receptors such as Serotonin, Adenosine, and Vanilloid.
CBD and Receptors
The stimulation of the TRPV-1 (Vanilloid) receptor by CBD influences a variety of processes including body temperature, inflammation, and pain perception.
Moreover, CBD is known to inhibit the functioning of FAAH enzyme that directly acts on the CB1 receptor and enables THC to produce its psychoactive effect. CBD has established global interest among industry specialists and its discovery has prompted medical experts to take a closer look at the benefits.
What Are CBD’s Benefits?
While studies are still trying to get to the heart of the matter, it does appear as some of the best CBD oils and other CBD products could have a plethora of medical benefits.
As a society, we are developing an over-reliance on pain medication to deal with issues such as inflammation. According to a study in the Journal of Experimental Medicine , CBD reduced the levels of chronic inflammation in rats and mice. CBD has also been known to help with chronic pain conditions such as fibromyalgia and multiple sclerosis.
Mental Health Disorders
A study published in Current Pharmaceutical Design suggested that CBD had a similar effect to certain antipsychotic drugs. Further studies showed that CBD could have a positive impact when used on people with neurological disorders. It also has potential anti-seizure properties and is used by individuals with epilepsy.
The above is just a taste of what CBD can do to help with certain medical ailments. Let’s take a look now at how it is extracted from the cannabis plant.
CBD Extraction Methods
The purpose of CBD extraction is quite simple; to end up with the cannabinoid (and others) in a highly concentrated form to make it suitable for human consumption.
To achieve this, you must use a plant material rich in CBD such as special cannabis strains or hemp. Special cannabis strains such as AC/DC and Charlotte’s Web have a high CBD concentration (up to 18% in some cases) and a low THC concentration (as little as 5%). You need a favorable CBD/THC ratio because even in cases where plants have a THC concentration of up to 6%, the extra high CBD content should hopefully render the psychoactive effects of THC inert.
Industrial Strains and Extraction
Various strains of industrial hemp can also be used to extract CBD. They are grown around the world legally; including in India, China and several countries in Western Europe. One of the most popular industrial hemp strains is Fedora 17. It has a low THC content which means any CBD extracted from it should have no psychoactive effects.
CBD oil made from hemp is legal in almost every country around the world including in all 50 states in the U.S. because of the negligible THC content.
Without further ado, let’s look at the 4 most common CBD oil extraction methods:
CBD Extraction Methods:
1 – The CO2 Cannabis Extraction Method
This form of CBD extraction is actually divided into supercritical, subcritical and ‘mid-critical’ categories but supercritical is by far the most commonly used. In fact, it is the most regularly used extraction method of all because it is safe and provides a pure end product.
In simple terms, CO2 cannabis extraction uses pressurized carbon dioxide (CO2) to pull CBD (and other phytochemicals) from the plant. CO2 acts like a solvent at certain temperatures and pressures but possesses none of the dangers. While it is safe and effective, it also involves expensive equipment which freezes the CO2 gas and compresses it into a supercritical cold liquid state.
CO2 & Extraction
CO2 typically behaves like a gas at standard pressure and temperature, and is easily changed to a solid while in this state; the solid version of the gas is known as dry ice. Using the aforementioned equipment in a lab, you can turn CO2 gas into a liquid by ensuring the temperature drops below -69 degrees Fahrenheit while increasing the pressure to over 75 pounds per square inch (psi). At this stage, you have your starting point for CO2 Cannabis extraction.
Once you have the liquid CO2, the next step is to increase the temperature and pressure past the point where the liquid becomes ‘supercritical.’ This term means the CO2 is now capable of adopting properties halfway between a gas and liquid simultaneously. Effectively, the supercritical CO2 is capable of filling a container (like gas) while also maintaining density (like a liquid). When CO2 is in its supercritical state, it is ideal for chemical extraction because it won’t cause the denaturing or damage that would make the CBD unfit for human consumption.
Liquid CO2 and the Extraction Process
Regarding extracting the CBD oil using this technique, you simply begin with liquid CO2 and raise its pressure via a compressor. You must also raise its temperature using a heater. The next step involves passing the supercritical carbon dioxide through some high-quality cannabis. Now, the CO2 will pull the essential trichomes (the sugary looking coating of the cannabis plant) and terpene oils (essential oils) out of the plant.
The solution gets passed via a separator and is broken down into its requisite parts. The good stuff (including trichomes and terpenes) is sent to the collection container. Meanwhile, the supercritical CO2 goes through a condenser and is turned back into a liquid. Finally, the liquid goes to a special storage tank and can be used to begin the process all over again.
This form of extraction involves low temperatures and low pressure. Subcritical extractions take longer than their supercritical counterparts and also produce a smaller yield. While it retains the terpenes, essential oils and other sensitive materials, it doesn’t extract larger molecules such as chlorophyll and omega 3 and 6. The benefit of subcritical extraction, however, is that it is less likely to damage terpenes.
Mid-critical is simply a general range between subcritical and supercritical. Some companies combine supercritical and subcritical to create a full-spectrum CO2 cannabis extract . They use the subcritical extraction method to separate the drawn-out oil and draw out the very same plant material using supercritical pressure. The oils are then homogenized into one which creates an amalgamated oil. This is known as the CO2 Total Extraction Process.
Pros and Cons of CO2 Cannabis Extraction
|Pros||Safety: CO2 is a common food additive and is used to produce things like carbonated soft drinks.||Effectiveness: CO2 has been used as an extraction solvent for years by food companies. It is used to remove caffeine from coffee and as an extraction solvent when producing essential oils.||Purity: The cannabinoids produced are potent and free of chlorophyll with minimal risk of contaminants.|
|Cons||Expensive: You can only complete the process with the aid of extremely expensive equipment.||Technical Ability: CO2 Cannabis extraction is not something that should be attempted by an amateur chemist.|
2 – The Olive Oil Extraction Method
The first step in olive oil extraction, which can be performed at home, involves ensuring the raw plant material is decarboxylated . In layman’s terms, it means you have to heat the plant to a certain temperature for a specific length of time to activate the plant’s chemicals.
Most experts recommend heating at 248 degrees Fahrenheit for 60 minutes or at 284 degrees Fahrenheit for 30 minutes. Once this step is completed, plant material is added to the olive oil and heated to 212 degrees Fahrenheit for up to 2 hours (and at least 1 hour). This process should result in the extraction of cannabinoids.
Pros and Cons of the Olive Oil Extraction Method
|Olive Oil Comparison||1||2|
|Pros||Very Safe: This method has been deemed safe and effective||Inexpensive: You can set everything up at home without breaking the bank.|
|Cons||Perishable: Regardless of whether your cannabis-infused oil is high in CBD or THC, it is highly perishable so you must store it in a cool, dark place and use as soon as possible.||Low Yields: This form of extraction only produces fairly low yields.|
3 – The Dry Ice Extraction Method
The dry ice extraction method is another method of CBD extraction that can be performed at home, although it takes a bit more time and effort than its olive oil equivalent. As well as the cannabis plant itself, you’ll need the following equipment:
- Around 3 pounds of dry ice
- A large piece of Plexiglas or a mirror
- A paint scraper or putty knife
- Thick gloves that are heat resistant and eye protection
- A clean 5-gallon plastic bucket
- 3 bubble hash mesh bags; sizes are 73, 160 and 220 microns
- 3 large, clean glass jars for storage
Put on your gloves and eye protection, chop up the cannabis plant into small pieces and place it in the bucket. Cover the plant with the dry ice and leave it for 3 minutes. It is best only to fill the bucket halfway. This process causes the freezing of the trichome resins. Fit the 73-micron bag over the bucket and shake the ice & plant combo for about 4 minutes; this knocks the frozen trichomes off.
Turn the bucket upside down on the Plexiglas and shake as much resin through the mesh bag as possible. Scrap the hash off the Plexiglas with your scraper and place it into one of the jars. Repeat with the 160 and 220-micron mesh bags, and you’ll be rewarded with three different strains of extract.
Pros and Cons of the Dry Ice Extraction Method
|Dry Ice Comparison||1||2||3|
|Pros||Ease of Use: The steps above are very easy to follow.||Clean: Unlike other methods, there is very little mess with dry ice extraction.||Decent Yield: You’ll end up with a lot more than if you use oil extraction.|
|Cons||Low-Quality: This is entirely dependent on the user, but you will ruin the quality of the product if you shake it for too long.||Not Always Easy Getting Dry Ice: Depending on where you live, it isn’t always so easy to get your hands on 3 pounds of dry ice unless you order it online.|
4 – The Solvent Extraction Method
Ethanol, low-grade alcohol, and butane are among the most common substances used in solvent extraction. Although ethanol extracts the full range of cannabinoids and terpenes from the plant, which makes the end product safe for consumption, it also extracts chlorophyll which may lead to some unpleasant side effects.
You can remove the chlorophyll by filtering the extract, but you significantly reduce the oil’s potency. Butane offers a stronger oil than ethanol, but it is more likely to contain solvents that could irritate the lungs.
For extraction, the liquid is added to the plant material. The extraction liquid will strip away the cannabinoids and flavor from the plant material but will probably take some green colorings too. Once enough cannabinoids have been extracted, heat the liquid to evaporate it down to the CBD base oil.
Pros and Cons of the Solvent Extraction Method
|Pros||Appropriate For Some Products: If you use high-grade alcohol, you may produce good quality oil.||Straightforward Process: Once you have the equipment, it isn’t difficult to complete.|
|Cons||Extremely Dangerous: Butane and Ethanol are flammable, so it isn’t worth starting a fire in your home to extract CBD in this manner.||Potentially Harmful: As well as destroying plant waxes, this form of extraction may produce oil that contains chlorophyll or other harmful contaminants.|
Final Words About CBD Extraction
It is extremely important to understand the various CBD extraction methods as they have a major impact on the quality of the end product; not to mention your health. We don’t recommend utilizing the solvent method because not only is it dangerous to make, it is also more likely to cause health problems. The cost of CO2 supercritical extraction means it is not possible for 99.9% of readers, but it is an excellent, safe and efficient method.
Those who create their own CBD oils will tend to use dry ice or olive oil, which provide great purity and are easy to do. There are also other extraction methods that we have not mentioned in this guide. If you have experience in extracting CBD from the cannabis plant and would like to share your method, feel free to contact us in the comments or through our Facebook page.
Those that are looking for high-quality CBD products from brands you can trust, feel free to view the list of top-rated brands below:
Most companies use the same routine methods, but here you'll find all you need to know about CBD Extractions. Which to look for, and which to avoid.
Ethanol Extraction vs. Supercritical CO2 [The Debate]
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Ethanol Extraction vs. Supercritical CO2 [The Debate]
- by Tyler Sewell
- 02 March, 2020
- 6 min read
- 0 Comments
- CBD Oil Products
- Hemp and CBD Oil Info
CBD Extraction Techniques: Supercritical CO2 or Ethanol?
The debate surrounding which CBD extraction method is superior rages on, and for good reason. Both supercritical CO2 and ethanol extraction have pros and cons. However, we feel our proprietary ethanol extraction is the best method for producing authentic full spectrum CBD oil. Additionally, our in-house chromatography technique enables us to selectively pull THC from our oil, creating a unique broad spectrum (THC free) CBD oil.
Here, we break down the differences between the two most commonly used CBD extraction methods (ethanol vs. CO2) to help clear the air.
Extraction methods are various processes used to procure and concentrate the medicinal compounds found naturally in hemp.
There is no absolute ‘best method’ when it comes to CBD extraction methods, and it truly depends on what you’re trying to create. In a nutshell, supercritical CO2 is used for producing highly-refined CBD isolates.
In contrast, ethanol is the go-to when opting for a full-spectrum CBD oil with a wide range of beneficial phytonutrients.
Supercritical carbon dioxide (CO2) extraction has exploded in popularity and is arguably the most common choice amongst CBD companies. The question remains, though, as to whether or not that’s a good thing. Let’s explore this topic further.
Supercritical Carbon-Dioxide (CO2) CBD Extraction
Supercritical CO2 extraction requires the use of costly and technologically advanced equipment, and also a well-trained technician to operate the machine.
This particular technology has applications in many areas other than hemp, such as:
- Sterilizing tissues and organs for transplants
- Extracting fat from snack foods
- Removing caffeine from coffee to make decaf
- Extracting flavor oils from hops
This process involves starting with gaseous CO2 and transforming it into a liquid by cooling it to under -69°F (-56°C) and applying 75 pounds of pressure per square inch.
At this point, the CO2 is now liquid, so the technician gradually increases the temperature and pressure until the fluid reaches a ‘supercritical’ state, meaning that it possesses both the properties of a gas and a liquid.
This dynamic allows for the supercritical CO2 to fill up a chamber like a gas, but soak the extraction material (hemp) like a liquid.
CO2 extraction is recognized in the cannabis industry for having an incredibly low environmental impact. Compared to a butane/propane extraction, CO2 is promoted as one of the safest techniques. However, despite these positives, CO2 is not without its flaws.
After the CO2 passes over the hemp, it goes through a separation chamber, where changes in temperature and pressure allow the CO2 to evaporate and leave behind cannabinoids, terpenes, and wax. The CO2 vapor then passes through a condenser to be returned to its liquid state and saved for future use.
CO2 extraction is often marketed as ‘solvent-free,’ suggesting it is a cleaner alternative to other extraction methods. However, this is usually not the case.
The resulting extract, while full of cannabinoids and terpenes, requires winterization due to the high content of wax and lipids. The most commonly used solvents for this purpose are ethanol (ironic), isopropanol (petroleum-based), or methanol (toxic wood-alcohol).
Most companies using CO2 extractions perform winterization through distillation, which is typically performed at very high heat. In this common method the two benefits of CO2 are lost; a solvent is still employed (“solvent free” therefore is not accurate) and the hemp extract is subjected to high heat (the cold benefits of CO2 are lost).
Furthermore, (and more importantly if you are consuming hemp-derived products for therapeutic benefits), this lengthy purification process, which is required to remove the co-extracted constituents (waxes and plant fats) from the extract, can take away from the final cannabinoid and terpenoid profile.
A study published by Planta Medica in March of 2018 found that CO2 extraction drastically changed the chemical composition of cannabis. Compared with the dried plant flower, CO2 extracts eliminated many of the subtle flavor and aroma molecules that provide nuance and subtlety to the experiential effects of different cultivars.
Advocates of CO2 extraction tout the non-polar nature of carbon-dioxide, meaning that it doesn’t pull out any of the water-soluble components in hemp.
However, this is only a benefit if your end goal is to make CBD isolate, as most experts agree that the full range of compounds found in hemp provides a unique therapeutic synergy known as the ‘entourage effect.’
One sure benefit of this method is that CO2 effectively eliminates any unwanted microbes, assuring that the end product is free from mold and mildew.
While it is a fairly rare occurrence, there are unfortunate deaths related to CO2 extraction from time to time, as a leak of carbon dioxide can go undetected due to the lack of smell or visible fumes – which can ultimately lead to a deadly build-up of CO2 in the environment, causing asphyxiation.
Alcohol (Ethanol) CBD Extraction
Cannabis is a fascinating plant that can produce more than 500 compounds that represent almost every biogenetic class. As such, we choose to utilize ethanol extraction to create the most full-spectrum CBD product possible.
Ethanol is simply, alcohol. It is made from plant fermentation and is a by-product of plants themselves.
Ethanol is a polar solvent, allowing it to extract both water and fat-soluble plant compounds, such as:
- Cannabinoids (CBD, THC, CBC, CBG, CBDV)
- Terpenes (myrcene, limonene, pinene, linalool, b-caryophyllene, terpinene, eucalyptol)
- Flavonoids (apigenin, luteolin, kaempferol, quercetin, and cannflavin A and B)
- Amino acids (all eight essentials)
- Alkamides (immune-promoting compounds)
In our ethanol extraction, food-grade ethanol is passed through the hemp flowers and brought to a very low boil. During this simmer, we gently cradle the flowers as they mix with the ethanol and create natural friction, producing a vapor that is full of beneficial compounds. We then recirculate the ethanol through the plant matter multiple times, allowing for maximum extraction.
Our sophisticated ethanol extraction process effectively removes undesirable plant waxes and chlorophyll without the high-heat exposure used in other extraction methods.
Ethanol has been referred to as “the best of both worlds”. This extraction method is recognized for having the efficiency of a butane extraction while maintaining the safety of CO2. The FDA classifies ethanol as safe for human consumption and therefore it is commonly used as a food preservative and food additive.
Now that we’ve talked in-depth about the two primary extraction techniques, let’s discuss the bottom line on choosing which extraction method you should look for in your CBD products.
Petroleum-Based Hemp Extraction
Petroleum-based solvents, such as Butane and Propane, were among the first extraction methods used by farmers, cannabis growers and home-grown CBD enthusiasts. These solvents work well due to their non-polarity, meaning they allow for the extraction of all the desired compounds (such as cannabinoids and terpenes) from the plant material without also extracting undesirable compounds (such as chlorophyll and plant metabolites). The problem with this extraction process is that it involves high heat and high pressure, is highly combustible and highly toxic, ruling out being a viable option by many health and wellness companies.
While petroleum-based solvents have their purpose, in a commercial setting, typically a solvent-based approach or a super critical (CO2) extraction are performed for feasibility and cost efficiencies.
How Do We Ensure Our Products are Clean and Solvent-Free?
We employ distillation techniques to remove the solvent from the extract. Our testing protocols test down to 1 part per million (1ppm) in which no ethanol is found in our extracts.
We strive to keep our products as natural and as close to the hemp plant as possible. Ethanol is well-known in the herbalism world to be the most natural and efficient solvent to get the most beneficial compounds from the plants. These methods have been employed for hundreds, if not thousands of years which is why most of the larger herbal companies are still using ethanol extraction over CO2.
The cannabis industry will continue to emerge with new technologies, making consumption more efficient, effective and more accessible. However, this doesn’t always equate to a better solution for extraction. We have found what works best for us in order to provide our customers with the healthiest products that have true therapeutic potential.
We passionately believe the 500+ phytonutrients extracted from hemp via ethanol extraction offer a far superior user experience to the isolated CBD that results from CO2 technology.
However, some people may prefer to use CBD isolate, due to the perceived ‘purity’ or ‘simplicity’ it offers. While we at Ananda Hemp certainly advocate for the use of full spectrum, ethanol extracted CBD, there is nothing wrong with using CO2 extracted isolate if that is what you prefer.
As always, do your research and make sure to read CoA’s thoroughly.
Our CBD Fact Sheet on Ethanol Extraction and Supercritical CO2 breaks down the important facts to know when you're looking to buy the best CBD oil available.