What You Need to Know About Cannabis Extraction Methods
The focus of any extraction process is to create a powerhouse product that surpasses the basic plant material. Here are just a few of the cannabis extraction methods commonly used, including the benefits and drawbacks of ethanol/alcohol, CO2, BHO, and dry sieving.
In recent years, cannabis extracts have become commonplace. Walk into any dispensary and you will be beset with a bevy of concentrates. Just to name a few, you can choose from wax, rosin, sugar, crumble, honeycomb, honey oil, shatter, budder, sauce, edibles, and oils.
All of these products are extracted forms of cannabis and exceptionally potent. They contain high levels of tetrahydrocannabinol (THC), cannabidiol (CBD) hemp oil, terpenes, trichomes, and other cannabinoids.
The modern and popular method of utilizing cannabis concentrates known as dabbing has also made cannabis extracts wildly popular. Dab concentrates typically contain levels of THC that range from 60 to 90 per cent. To attain such high potency, cannabis extraction methods have evolved dramatically in recent years and have been honed to a science.
The focus of any extraction process is to create a powerhouse product that surpasses the basic plant material. However, when the product is properly extracted, it should still retain the tastes and effects of the plant. Some concentrates even continue to smell like cannabis, while others have little or no odor, which is often more desirable to some users just starting out.
The extraction techniques used to gather cannabis concentrates are typically performed by trained professionals in laboratory settings because not all methods are safe and some are quite complex.
Ethanol or Alcohol Extraction
Ethanol extraction, also called alcohol extraction, is probably one of the oldest extraction methods used to pull out the plant's full-bodied oils. The cannabis plant material is soaked in an ethanol solution for varying amounts of time.
In the early days of cannabis extraction, the solution was simply heated in hot water and the ethanol allowed to evaporate into the air. However, nowadays, a specialized machine is normally utilized to heat the mixture so that when the ethanol starts to evaporate from the plant’s oil, it can then recaptured for later reuse.
Cannabis oil extracted using ethanol is typically used to create cannabis tinctures and edibles. Unfortunately, it is of often hard to remove all traces of the ethanol from the concentrate. Frequently, carbon filtration is also tried to further clean away the ethanol.
Butane extraction is a form of hydrocarbon extraction, which is the process of using a hydrocarbon like butane or propane as the solvent to extract cannabis concentrates. Butane is the most popular style of extraction used to create cannabis concentrates. Its popularity heralds from its ease and cost-effectiveness. The method requires no fancy machinery and despite the combustible nature of butane, it remains a common at-home extraction technique.
The butane extract method involves filling a glass cylinder with marijuana. The plant material is tightly packed into the glass tube. At one end of the tube, a screen is affixed so the plant material does not fall out. The screened end of the tube is then held over a glass receptacle. A butane torch is affixed to the other end of the glass tube. Butane is blown into the tube. The heated cannabis plant material then starts to release its oils and resins, which seep out the screened end of the tube and into the waiting container.
The butane must then be purged from the oil to create a clean product. The oil solution is heated in exceptionally hot water The butane bubbles form in the oil and when they pop they are released as gas into the atmosphere.
When cooled the remaining product is known as butane hash oil (BHO). It is what is commonly used to create shatter, glass, wax, honey oil, nug run, hash, budder, and a variety of other cannabis concentrates.
Many BHO advocates argue that butane is a clean and safe way to create cannabis concentrates; however, others feel that even a small amount of chemical solvents in the concentrate are unacceptable.
It is typically argued that BHO products are harsher on the lungs – even when vaporized. Suffers of respiratory issues often opt to forego petroleum solvent-based extraction concentrates for cleaner alternatives because they fear residual solvents might remain in the concentrate.
Supercritical fluid extraction is commonly referred to simply as CO2 extraction. The method is solvent-free and is used to create premium concentrates that are loved by cannabis connoisseurs because they retain the plant’s terpenes which create titillating flavors.
Unlike other extraction methods, CO2 extraction is non-toxic. It is also often the preferred method to create extractions that contain ample cannabinoids and CBD for medicinal use. Medicinal cannabis users generally turn to concentrates created through CO2 extraction for dabbing or vaporizing because it is considered to create a cleaner and more pure concentrate product than other methods.
With CO2 extraction, the plant material is placed into an extraction vessel. The CO2 liquid is forced through the plant material within the vessel. With optimal pressure and temperature, the plant’s terpenes and cannabinoids begin to separate. The CO2 turns from a gas into a liquid as it passes through the cannabis.
Using a combination of temperature and pressure, the supercritical liquid forms and the carbon dioxide becomes a solvent. The CO2 is cycled through the plant material numerous times to gather the desired cannabinoids and terpenes. The supercritical liquid is then allowed to return to gas where it can be collected for reuse or safely released into the atmosphere.
Once the CO2 extraction process is complete, a dark gooey resin is left behind. The science involved in CO2 extraction is complicated and takes a knowledgeable technician who is well versed in the various pressures and temperatures needed to attain the optimal flavors and cannabinoid levels needed to create the targeted product.
CO2 extraction is considered an eco-friendly method because the CO2 can safely be released into the atmosphere or it can be reclaimed and recycled for later use. However, it is a costly process. Many high-end cannabis products are created through CO2 extraction.
Dry Sieving Extraction
Dry sieving is an extraction method used to obtain kief or hashish. The extraction craft originated in the Middle East in such countries as Pakistan and Morocco. It involves rubbing the buds of the marijuana plant and some plant material across a variety of screens or mesh-like material that vary in gauge size. The screens/mesh break apart the plant’s trichomes from the fiber.
The trichomes fall through the screen as a sticky powdery substance. The paste-like substance is then used to create dry sieve hash. The hashish can be smoked or the substance used to manufacture other hash concentrates.
The science of cannabis extraction methods has one primary focus: to extract high concentrations of desirable compounds from the cannabis plant material. The rich resin can then be used in a mind-boggling assortment of concentrates that allow the cannabis user to target their specific needs and physical requirements more directly, such as deciding if they want high CBD/low THC levels or vice versa.
Concentrates also give medical researchers greater freedom to study the effects and benefits of the various cannabinoids, trichomes, and terpenes of the plant to design more targeted treatments for users.
As extraction methods emerge and grow, so will the diversity of concentrates. Ideally, more control will be obtained over dosage levels and usage options as the extraction approaches become fine-tuned.
The science of cannabis extraction continues to branch out and new extraction methods are on the horizon to meet the ever-changing needs of the marijuana movement.
Written by Mark S.