Cannabis (Marijuana & Hemp) have gained widespread attention in recent years for therapeutic and recreational potential. As more people explore the uses of this versatile plant, understanding cannabis extraction methods becomes crucial. These methods are at the heart of producing various cannabis products, from oils and tinctures to edibles and topicals. In this quick guide to cannabis extraction, we'll delve into the world of cannabis extraction, exploring a few primary methods and their respective advantages and disadvantages. We will cover Super Critical CO2 Extraction, Ethanol Extraction and Solvent-less Extraction. There are many subtle variations within these three categories but we will attempt to touch on the fundamentals.
So what exactly is "extraction"? Cannabis contains over 100 different cannabinoids, including the well-known THC (tetrahydrocannabinol) and CBD (cannabidiol). These compounds hold therapeutic value, but they are not readily accessible in their raw plant form. Cannabis extraction is the process of isolating and concentrating these compounds, making them easier to consume and utilize. Since these valuable plant compounds are not water soluble (dissolvable in water), it is necessary to use other methods, or a solvent, in order to separate them from the plant. The most common ways to do this are supercritical CO2 extraction, ethanal extraction or various solvent less methods.
Solvent-Based Extraction Solvent-based extraction is one of the oldest and most common methods of cannabis extraction. It involves using a solvent, such as ethanol, butane, propane, or CO2, to dissolve the cannabinoids and other desirable compounds from the cannabis plant. It is efficient and can produce high yields of cannabinoids. The resulting extracts can have a wide range of potencies and can be used in various products. For our purpose here, we will focus on supercritical CO2 and ethanol extraction because they are by far the most widely used solvent-based methods.
Supercritical CO2 Extraction
One of the most widely used methods of solvent-based extraction is called supercritical CO2 extraction. This method is known for its precision and ability to isolate specific compounds. CO2 (carbon dioxide) is a gas at ambient temperature and pressure. However, under specific conditions of temperature and pressure, it can exist in a state called "supercritical." In this state, CO2 exhibits properties of both a gas and a liquid, making it an ideal solvent for extracting compounds from plant material.
Equipment
Supercritical CO2 extraction systems consist of three main components: a CO2 storage tank, a high-pressure pump, and an extraction chamber. The CO2 is pressurized and heated to reach the supercritical state within the extraction chamber.
Process
In the extraction chamber, the supercritical CO2 is introduced to the cannabis plant material. The supercritical CO2 acts as a solvent, dissolving the cannabinoids, terpenes, and other desired compounds from the plant material.
Separation
After the extraction process is complete, the supercritical CO2, now loaded with the dissolved compounds, is moved to a separate chamber, often referred to as a separator. Here, the pressure and temperature are adjusted to allow the CO2 to revert back to a gaseous state. The CO2 is collected for reuse and the extracted compounds are left behind.
Collection
The extracted cannabinoids and other compounds are then collected and further processed to create various cannabis products, such as oils, tinctures, and concentrates. This resulting extract is often highly pure and free of residual solvents.
Advantages of Supercritical CO2 Extraction
Supercritical CO2 extraction is known for producing high-quality, pure extracts because CO2 is a selective solvent. It can be fine-tuned to target specific compounds, leaving behind unwanted components. This method is considered safe because it doesn't involve the use of flammable or toxic solvents. It eliminates the risk of residual solvents in the final product.
Environmental Friendliness: CO2 is a naturally occurring and abundant gas. It doesn't contribute to environmental pollution or greenhouse gas emissions when used in this extraction method.
Precise Control: Operators have precise control over temperature and pressure, allowing for the customization of the extraction process to target specific compounds or maintain the integrity of the strain's terpenes.
Disadvantages of Supercritical CO2 Extraction
The equipment required for supercritical CO2 extraction can be expensive and may not be accessible to small-scale producers. Operating a supercritical CO2 extraction system requires technical expertise and training due to the complexity of the machinery and the need for precise control.
Ethanol Extraction
Ethanol extraction is a solvent-based method that uses ethyl alcohol (ethanol) as the primary solvent. It's a versatile technique employed in various industries, including pharmaceuticals and food production, and it's particularly popular in cannabis extraction. Solvent Contact: The cannabis plant material (typically ground or chopped) is soaked or agitated in ethanol. Ethanol acts as a solvent, dissolving the cannabinoids, terpenes, and other desirable compounds from the plant material.
Equipment
The primary equipment used in ethanol extraction include a solvent tank, which holds the ethanol solvent, and an extraction vessel, to contain the plant material and dissolve the desired compounds. A chiller and a pump maintain low temperatures and circulate the solvent. Finally, a recovery system, such as a rotary evaporator or falling film evaporator, is employed to separate the ethanol from the extracted compounds, leaving behind a concentrated, purified extract.
Process
The extraction process usually takes place for a specific duration, allowing the ethanol to thoroughly interact with the plant material. The time can vary depending on the desired end product and the equipment used.
Separation
After the extraction period, the ethanol-cannabis mixture is typically filtered to remove solid plant material. This step separates the liquid extract from the remaining plant material.
Collection
The liquid extract, now containing dissolved cannabinoids and other compounds, goes through a process to remove the ethanol. This is often done through evaporation and distillation, resulting in a concentrated cannabis extract. To further refine the extract, additional purification steps might be employed, such as winterization to remove fats and lipids or fractional distillation to isolate specific compounds.
Advantages of Ethanol Extraction
Ethanol is considered a safe solvent for extraction because it is generally recognized as safe (GRAS) for consumption by the FDA. Ethanol can efficiently dissolve a wide range of cannabinoids and terpenes, resulting in a broad-spectrum extract. Ethanol extraction is suitable for a variety of cannabis products, from tinctures and oils to edibles and topicals. It's also adaptable for both small-scale and large-scale production. Operators have some control over the extraction process, including temperature and duration, allowing for customization of the final product.
Disadvantages of Ethanol Extraction
Ethanol has the tendency to extract chlorophyll, which can contribute to a bitter taste and a green color in the final product. Additional steps may be required to remove excess chlorophyll. Ethanol extraction at higher temperatures can result in the loss of some volatile terpenes, impacting the aroma and flavor of the final product. The ethanol extraction process can be more complex than some solventless methods like rosin pressing, and it may require specialized equipment. It's non-toxic when used appropriately but, does carry the same flammability risks as some other solvents.
Solventless Extraction
This is a cannabis extraction method that relies on mechanical techniques like heat and pressure to separate cannabinoids and terpenes from the plant material, completely avoiding the use of chemical solvents such as ethanol or CO2. This approach is valued for its purity, as it minimizes the risk of residual solvents in the final product and preserves the natural terpenes and flavors of the cannabis strain. Common solventless extraction methods include rosin pressing, where heat and pressure are applied to squeeze out cannabis compounds, ice water hash, which uses ice and water to separate trichomes, and dry sift, a process of mechanically separating resin glands from dried cannabis flowers through sifting and sieving techniques.
Rosin Pressing
This method of extraction involves placing raw cannabis flower between two heated metal plates and applying significant pressure. The combination of heat and pressure causes the cannabinoids and terpenes to melt and separate from the plant material. The resulting waxy extract, known as rosin, is collected on a surface like parchment paper or a silicone mat. This method is valued for its simplicity, safety, and preservation of terpenes.
Ice Water Hash
Also known as "bubble hash," this method utilizes ice and water to gently separate trichomes (resin glands) from the plant material. It this icy water bath, the frozen trichomes become brittle and can be easily separated through agitation. The mixture is then filtered through a series of micron screens, with each screen collecting trichomes of different sizes, resulting in various grades of hash. It's a gentle and natural method that produces high-quality, full-spectrum extracts.
Dry Sift
Dry sift extraction involves mechanically separating resin glands from dried cannabis flowers through sifting and sieving techniques. Dried cannabis material is crushed or ground and then gently agitated, and the trichomes, which contain cannabinoids and terpenes, fall through a series of screens or sieves with varying mesh sizes. The collected sifted material can be further refined to remove any residual plant material. This method is valued for its simplicity and effectiveness in producing solventless, high-potency extracts.
Advantages of Solventless Extraction Methods
Solventless extraction methods, including rosin pressing, ice water hash, and dry sift, offer numerous advantages. Firstly, they are prized for their purity, as they eliminate the use of chemical solvents, ensuring that the final products are free from potentially harmful residue. This can translate to safer and cleaner cannabis extracts, appealing to health-conscious consumers. Additionally, these methods preserve the natural terpenes, flavors, and aromas of the cannabis strain, resulting in a product with rich and authentic sensory characteristics. Solventless extraction techniques are also considered environmentally friendly, as they do not involve the use of hazardous solvents and are less energy-intensive. Furthermore, these methods are accessible to smaller-scale producers and DIY enthusiasts, allowing for artisanal and craft-level production.
Disadvantages of Solventless Extraction Methods
While solventless extraction methods offer many benefits, they come with certain limitations. One notable disadvantage is lower yields compared to some solvent-based methods, making them less cost-effective for large-scale production. The extraction process can also be more time-consuming and labor-intensive, as each batch of cannabis material must be processed individually. Achieving consistent results can be challenging due to variables such as temperature, pressure, and the quality of the starting material. Moreover, the equipment for some solventless methods, especially rosin pressing machines, can be relatively expensive, which may deter smaller operators. Finally, the physical nature of these techniques can result in product variability, affecting the texture and appearance of the final extract, which might not meet the aesthetics expected by some consumers.
Conclusion
Understanding cannabis extraction methods is valuable for informed consumers and producers alike. Each method has its strengths and weaknesses, and the choice depends on the desired product, safety considerations, and scalability. As the cannabis and hemp industries continue to evolve, innovations in extraction techniques are likely to emerge, providing even more options for creating diverse and potent cannabis products. Whether you're seeking pain relief, relaxation, or a recreational experience, knowing how your favorite cannabis products are made empowers you to make informed choices and enjoy the plant's benefits responsibly. This quick guide to extraction only scratches the surface of the complex science of cannabis extraction and we encourage you to learn more if you are interested!
Here at Wild Fox, we use ethanol extraction. We have also used supercritical CO2 extraction in the past. However, ethanol extraction is more readily available to us through our extraction partners locally and it is more affordable to us as a small producer. We always subject our extract to third party purity testing for pesticides, microbial, mycotoxins and residual solvents before ever using the extract to formulate our products. We are also always happy to answer any questions about our process so please don't hesitate to pickup the phone or shoot us an email!
Thanks!
-Ben and Karah
