How It's Made: CBD Extraction Methods, Explained
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As of late, CBD has been enjoying a surge in popularity among consumers, and the growing interest has, of course, also driven the growth of the CBD market and industry. Its usage and production is only expected to rise further in coming years, and it’s already a bustling market worldwide. With such demand, CBD farmers, manufacturers and retailers have stepped up to increase efficiency and quality at every stage of the supply chain, and increase the quality of the final products that get to consumers.
One of these stages - the process of extracting CBD from the cannabis plant and processed into a safe and consumable product - is a crucial part of the CBD manufacturing process. There are multiple different methods of extraction that have been developed over the years, and they play a big part in the quality of the resulting CBD oil. We’re here to break down the more prominent methods for the average consumer, so you know what goes into your CBD and what to look for in your search.
Cannabidiol and you
First, let’s get down to brass tacks for anyone unfamiliar. Cannabidiol (CBD) is a compound produced by the plant Cannabis sativa - and is what is termed a ‘cannabinoid’. It is one of 120 cannabinoids found in cannabis, amongst other varied compounds like terpenes which are also naturally produced by the plant.
It is one of the most abundant compounds in the cannabis plant, typically comprising around 40% of the plant extract’s chemical composition, and people are taking CBD for a range of issues including improving mood, relieving stress, aiding in appetite and sleep, and easing pain and anxiety. Research is currently being carried out into how CBD can affect the body, but it is thought to have the ability to support and maintain health in various ways. It’s even used in a certified medical treatment for two rare types of epilepsy, to help with symptoms and seizures. CBD is also non-toxic and non-neurotropic nature, in contrast to its fellow cannabinoid tetrahydrocannabinol (THC) - so when it’s taken, it doesn’t induce the altered state of heightened sensory perception and euphoria that you typically see with cannabis usage. CBD is even thought to have non-addictive properties, and people who use it in the long-term are less likely to build up a tolerance to it compared to other substances.
Naturally, with all these benefits that CBD can offer, it’s been incorporated into a wide array of different products. Humans have been cultivating cannabis and enjoying the effects of CBD throughout history, but it’s only been in more recent decades as technology and science have developed and innovated new practices that we have been able to actually separate and investigate individual cannabis plant compounds. Such methods of extraction, refined and scaled up for commercial usage, are how we obtain CBD, and with that refined product we can infuse CBD into everything from creams to foods to vapes, making it accessible for people like never before.
The manufacturing process: a primer
The manufacturing process for any cannabis-derived product, CBD included, is complex. It’s a multi-step affair that goes through several different stages, all with their own separate equipment needed to carry out the processing. The process from beginning to end spans many months, from growing the plants themselves to extracting the CBD, and finally to incorporating it into the final product for sale.
CBD manufacturing relies on the herbal raw material hemp, which is the term used to describe cannabis plants and varieties that have high levels of CBD and lower levels of THC. However, this means that inconsistencies between batches are a frequent occurrence which manufacturers have to deal with by troubleshooting and adjusting steps as they go. A high quality manufacturer will invest the time, effort and resources necessary to ensure a measure of consistency across their products.
To provide a quick summary, here are each of the stages of the manufacturing process before packaging and distribution:
- Cultivar selection – cultivation
- Cultivation – growing the hemp plants
- Processing – harvesting, drying and processing hemp
- Selecting Quality Extraction Material – testing and selecting hemp
- Extraction– extraction of compounds from hemp
- Refinement – further processing of extract
- Isolation – separation of CBD from the extract
- Formulation - incorporating the CBD into a final product
Selecting the appropriate cultivar of cannabis and cultivating the plants themselves is the most time-consuming portion of the manufacturing process. Depending on which cannabis plant variety is being grown, the facilities used will differ, but for harvesting CBD the cultivars chosen will typically be high CBD, low THC, hemp. This is usually cultivated outdoors on speciality farms, or sometimes in greenhouses or indoors. Industrial hemp may also be used, but that typically has lower levels of CBD and higher risks of containing contaminants.
Once cultivated and grown, the plants are trimmed and the material is dried. After this “raw material” is prepared, it is sent to the processing and manufacturing facility for the next stage. The raw material is tested and inspected, to account for any potential variability, heterogeneity or inconsistency of the material and to make sure that it is suitable for use. The raw hemp material is then ground to break it down into smaller particles, increasing surface area and optimising efficiency for the next stage - extraction. Here, the chemicals present in the plant are separated from the biomass, a process we will elaborate on further in the next section.
The extract is then put through the “dewaxing” process to remove waxes, plant pigments and other impurities present in the extract, subsequent filtration to further remove non-active components, a solvent removal process, and then a final distillation to concentrate and purify the cannabinoids. From there, the CBD can even be isolated as crystals. This pure CBD isolate can then be added into the product of the manufacturer’s design, packaged, tested, and distributed out for sale.
Each different stage of the manufacturing process is its own industry, and just as hemp farmers continue to refine their methods of cultivating and growing their crops, the CBD processing industry has invested into developing multiple different methods of extraction. Ultimately, the extraction process will be decisive in the quality and purity of your final CBD oil and it’s thus crucial to take into account.
There are some key factors that manufacturers use to differentiate and decide which CBD extraction option is right for them. They are:
- Solvent- what substance will be used to separate the chemicals you want from the plant biomass?
- Design- what equipment is appropriate to handle the solvent you are using?
- Purpose- what intended purpose is your equipment built and designed for?
- Facility- what kind of facilities are appropriate for processing the extracted solvent?
- Consumption- is the solvent being used safe for consumption?
When it comes to solvent, there is a range of different solvents that have been developed and used since the birth of the industry. All of these have different properties that decide how the extraction process itself is carried out, and have varying efficiency and yields. Pretty much all commercially used solvents are ‘Generally Regarded as Safe (GRAS) by the FDA on some level, but some may be approved for consumption while others only for specific uses, and different countries and states have different rules and regulations on the safe levels of residual solvent.
Design and purpose pertain to the equipment itself - it’s vital that it is constructed for the purpose of the extraction process. Stainless steel is generally the material of choice for CBD extraction and any other food or edible oil applications, as it prevents corrosion. The equipment also differs depending on whether or not the solvent is flammable, the pressure rating necessary for the solvent, as well as the overpressure protection and other safety measures to protect the workers and operators handling the equipment. The equipment also needs to be food grade, and have accessibility to allow for proper cleaning. Additionally, the facilities need to be designed to accommodate equipment and processing.
All of these requirements can drive up the price of operation, and different methods can also be more difficult to put into practice or automate, which for some manufacturers can be a significant drawback.
With any method, the end result of extraction is a series of fractioned cannabinoid and terpene extracts, which will need to be further processed and refined. The extract - at this stage, referred to as raw crude - contains all of the necessary active ingredients that a manufacturer desires, allowing for them to select which will be used in the final product, which will be whittled down in the refinement stage.
CO2 Extraction: supercritical and subcritical
You likely are very familiar with CO2, the ubiquitous gas in the air we breathe, but it may initially seem a little left field to use it as a way of dissolving compounds out of plant material. As surprising as it may seem, this technique has become extremely popular in many industries, especially food processing. Usually referred to by its shortened moniker of CO2 extraction, this method relies upon supercritical carbon dioxide (CO2) to extract the desired compounds from a cannabis plant. As a solvent it’s classified GRAS by the FDA for consumption, making it completely safe for use, and it’s also non-flammable, non-toxic, and environmentally benign.
Supercritical, by definition, means “above a certain threshold”. A supercritical fluid is a substance that exists at a temperature and pressure that is beyond its critical point, blurring the line between distinct liquid and gas phases and possessing properties between the two. Such a fluid can effuse through solids like a gas, but also can dissolve materials like a liquid, and by changing the temperature and pressure of the fluid its properties can be “fine-tuned” to be more akin to either a liquid or a gas.
CO2, at specific high pressures and temperatures, becomes supercritical and can act as a solvent instead of an inert gas, which allows it to pass through raw materials and selectively dissolve specific compounds. In this case, this means CBD along with other cannabinoids, can be “pulled” from plant cells with a near 100% efficiency. The CO2 than can be extracted and sublimates once back at a normal atmospheric pressure, which yields a clean extract without residual solvents in the mix. It’s a method with fast extraction times and great efficacy.
The intensity of supercritical CO2 extraction, however, does necessitate a lengthy additional process to remove any unwanted compounds that are present in the extract so it won’t go into the final product later. The first step of this is termed winterization. Here, the crude extracted mixture is combined with high-proof alcohol, stirred vigorously to mix it, and then left overnight in a deep freezer. The mixture is cloudy and ready for filtration by the next morning, put through a funnel or filter paper to filter to satisfaction, and then the entire extraction warmed in order to evaporate the alcohol solvent for further use. The CBD extract can be further refined through short path distillation, where it’s heated and each compound is separated in order of their different boiling points. This allows for isolation of the individual compounds, CBD included.
CO2 extraction can also come in the form of subcritical CO2 extraction. The solvency power in this method is lower, resulting in a very different end-product in which mostly lighter oils are pulled out and resins and waxes are left behind. It is, however, less common as supercritical CO2 extraction as it is a longer process with a lower yield. However as the extraction is conducted at colder temperatures, it’s very effective in extracting more temperature-sensitive compounds like volatile oils and terpenes, thus preserving them for use.
The equipment required for CO2 extraction, including a CO2 extractor, are generally expensive and high quality equipment is priced competitively. Less costly equipment also has slower rates of extraction, which impedes the manufacturing process as a whole. It also requires operators to be highly trained and experienced to handle the equipment. However, there are minimal facility safety requirements and costs for this method - just signs and a CO2 monitor are required - which allows for automation to be easy and available to most manufacturers.
The selectivity and ability to modify the process according to different molecular weights gives this method great versatility, and the lack of any residual solvent left behind after extraction makes it ideal for producing CBD vapes. The sheer efficiency is also what draws many to this method - studies say that CO2 extraction can have as much as 92% efficiency. It’s a cleaner, purer, more effective form of extraction that allows for high-quality CBD to be made, which is why it’s so popular amongst manufacturers in the current market.
Possibly the oldest form of extraction, ethanol extraction uses ethanol in order to strip CBD from the plant. The solvent in question can be any high profile alcohol, but is most commonly ethanol, hence the name.
Ethanol is approved GRAS by the FDA for consumption and is commonly used as a food preservative and additive in many products. It is a polar solvent - meaning that it can mix with water and is capable of dissolving water-soluble molecules, as well as dissolving the cannabis compounds a manufacturer wants to target. By soaking certain materials in ethanol or alcohol and leaving it for a certain amount of time, the biochemistry changes and cannabinoids and other beneficial compounds can be drawn out.
The quality of the alcohol being used matters - using a high-proof is crucial in order to minimise any potential damage done to the cannabinoids and suspends them in a medium that prevents oxidation or other damaging processes from occurring. Chlorophyll also ends up getting pulled out, which lends the resulting extract oil a reportedly grassy and bitter flavour. This chlorophyll can be pretty easily removed with some additional post-extraction filtering, but this process can strip away some of the cannabinoids in the extract and reduce the quality of the final oil.
Ethanol extraction does require more work and care in execution, and further steps of refinement and filtration are necessary. When done properly though, a manufacturer can cut out the need for winterization and thus improve efficiency of the manufacturing process on the whole. It’s also an easily scalable method, and obtainable for those working at a smaller scale of production.
It’s a great method for creating full-spectrum hemp extracts that include all cannabinoids in the plant, not just CBD, and is lower-cost, efficient and safe. When done well, it’s even comparable to CO2 extraction in quality. It’s a method still used by many companies on the market today, and in the hands of experienced operators can be used successfully and consistently to create high-quality extracts for products. However, it comes with the caveat of a greater amount of expertise required for the method to work well, and the necessity of post-extraction processing. Less experienced extractors run the risk of solvent contamination, more chance of errors, and a greater likelihood of a lower quality end product.
This method is also called the Rick Simpson Method, after the first man to initially use it. This is one of the earlier extraction methods, created using a light hydrocarbon as the solvent of choice to extract cannabis oil. The hydrocarbon solvent in question is usually butane, pentane, propane, hexane, isopropyl alcohol or acetone, which all have low boiling points.
The plant material is submerged in the solvent, and allowed to steep as the compounds are stripped and left in a liquid form. The low boiling point of the hydrocarbons allows for them to be subsequently boiled to evaporation, thus leaving behind CBD oil.
This is one of the cheapest and most straightforward methods of extraction, and can be done with more affordable equipment compared to CO2 extraction. The rate at which the extraction is carried out is fast, and the final extract is generally quite potent.
It is, however, detrimental when your purpose is isolating CBD. The resulting oil usually has a lower concentration of desirable terpenes and cannabinoids like CBD, but a higher concentration of THC. The hydrocarbon solvents are highly flammable, making the process itself hazardous, and in addition, this method destroys certain plant waxes and can result in harmful residues being left behind and contaminating the extract. It’s also difficult and expensive to automate this method, and there’s difficulty scaling it up because the amount of hydrocarbon that can be on-site is limited by law.
The challenges, inefficiency and danger inherent to this method is why it’s fallen out of practice, and is rarely used by any modern commercial CBD companies. The handful that do use it need to be heavily scrutinized and tested by local regulators and inspectors.
Water, in many respects, can be considered the universal solvent - it’s the first liquid that comes to mind when you think of dissolving anything. Some manufacturers have figured out how to use heated water vapour to extract cannabinoids from hemp.
With steam distillation, steam is the solvent of choice for separating CBD oil from the plant. As water boils in a container, it turns into steam, which bubbles up through into a flask holding the plant matter. Saturated steam passes through the cannabis plant, pulling out the volatile oils along with it in gaseous form. From there it passes into a condenser tube, where it is captured and condenses back into oil and water, and this oil-and-water mixture can be handily distilled to extract the CBD oil itself.
This method is comparatively inexpensive and is a tried and true method that can reward manufacturers with a high yield when carried out properly. It’s been used and developed in the perfume industry for centuries to extract essential oils. However, for cannabis and CBD it’s less popular because of its inefficiency for extracting CBD. For steam distillation to work, it requires much larger quantities of hemp material than other methods, and it’s more difficult to try and extract exact amounts of CBD concentrations. Additionally, the steam itself can be a source of error - if it gets too hot, it can damage the extract and fundamentally alter the chemical properties of the cannabinoids within, degrading the quality of the final CBD oil.
So which extraction method is best?
When you’re looking for CBD products, factoring in the method of manufacture and the extraction method the company uses is important. It can be a clear indicator as to quality and the actual value of their products.
Cases can be made for certain methods over the others - ethanol extraction is excellent for companies just starting thanks to its relative cost-effectiveness without sacrificing quality or safety. When it comes down to it, though, supercritical CO2 extraction is the best possible method of extracting CBD on the commercial scale, for both company and consumer. It’s completely safe for consumption, as all the solvent or residue is completely removed, and it creates very little waste for the company itself. Though the costs of production and the quality of the end product drive up the price, CBD extracted in this manner will contain no harsh chemicals or contaminants and is as pure as pure can get in the commercial market.
Other extraction methods can produce safe and high-quality products as well, but they tend to run with more risk due to the mechanisms of their manufacture. For instance, residual solvents in hydrocarbon extraction can potentially be dangerous to health. Steam distillation and ethanol extraction are lower-risk, but tend to yield lower or inconsistent amounts of CBD. CO2 extraction products are usually more expensive, but many consider it a small price to pay for greater quality and assurance of safety.
The best for you
If you’re interested in purchasing CBD products made with CO2 extraction technology, be sure to check out Amphora’s CBD-infused vapes. Vaping is one of the best ways to get the most out of your CBD, thanks to its fast-acting mechanism and its efficacy, and it’s great for those who have busy schedules or simply can’t wait to feel the therapeutic effects of CBD.
We at Amphora offer a selection of holistic, all-natural CBD vape cartridges, each designed to aid in a different aspect of daily life. Made using supercritical CO2 extraction technology, our CBD is also sourced entirely from organically-grown hemp plants, and our vape oil contains natural organic CBD distillate and selected terpenes for flavour and wellness with no additives or THC included. Our products go through stringent third-party laboratory testing to be held to the highest standard, At every stage of the manufacturing process, we endeavour to ensure safety and quality so you can enjoy your CBD vape experience without worry.
Written by | Infused Amphora Team
The Infused Amphora Team is dedicated to creating resources to educate and engage consumers on the growing evidence of CBD benefits and the extensive health and wellness properties of CBD Oil.
Contributor | Angus Taylor CEO
Infused Amphora “Learn” is intended for informational purposes only and is NOT a substitute for professional medical advice, diagnosis or treatment.