Medical Cannabis Extractions
What are cannabis extractions?
Cannabis extractions (cannabis oil, budder, wax, honeycomb etc) are the cannabinoids of the cannabis plant that have been extracted using one of many known extraction methods, some of which are described below. They are significantly more potent than regular flowers and their applications in medicine have proven to be more diverse and many times more effective.
How are cannabis extractions extracted?
Cannabinoids are not water soluble, so to extract them properly the cannabinoids must be mechanically separated or dissolved in a solvent.
What are solvents?
Solvents are the chemicals used to remove the cannabinoids from the cannabis plant. Butane, hexane, isopropyl alcohol and ethanol are all solvents that are commonly used in cannabis extractions. When cannabis flowers are submerged in these solvents, the cannabinoids, terpenes and other active ingredients are dissolved into the liquid or gas solvent. The remaining solid plant matter is filtered out and the liquid solvent and cannabinoid mixture is purged to remove all solvents, leaving only cannabinoids and other active compounds of the cannabis plant.
Why is removal of solvents important?
Incredible scientific precision is required to properly remove all trace solvents from a cannabis concentrate. Any residual solvents can be harmful to patients, which is why AMCS offers residual solvent testing to dispensaries and manufacturers who are concerned with compliance and the safety of their cannabis extractions. Different extraction methods are used to create cannabis extractions, all with varying degrees of effectiveness.
Can you tell me more about the various method of extraction?
Dry Sieve
The most naturally and unobtrusive form of cannabis extraction, a lowish yield and the meticulous process involved in removing the cannabinoid containing trichomes from the plant matter.
There are many grades of dry sieve or what is often times referred to as “kief”, a mixture of glandular trichome heads, stalks and plant material, up to “Full-melt Dry Sieve” which generally contains just the trichome heads themselves.
There are multiple ways to achieve dry sieved products, but more often than not a single silk screen or series of silk screens can be utilized in conjunction with agitation to separate trichomes from the plant material creating a smokable, edible, or vaporizable cannabis concentrate.
Water
Very much like the dry sieve process, water can be used in conjunction with screens as a vessel to carry mechanically separated trichomes through multiple micron level screens. A micron is a microscopic unit of measurement used to calculate the size of the trichrome and thus the holes in the screens themselves.
Water hash
also termed “Bubble-hash” and other names is made using agitation, generally from ice and motion, either done by hand or utilizing a washing machine to gently break off the trichome heads from the plant material. Water extracted products must be broken down and dried thoroughly before being consumed or there is the be possibility of mold and health risks due to improper storage.
CO 2
Arguably the least-toxic form of cannabis extractions, CO 2 (carbon dioxide) has become more popular as an extraction method because of its low environmental impact and nonexistent toxicity; however, CO 2 extraction systems are considerably more expensive than butane or hexane systems.
Most people tend to prefer subcritical CO 2 extracts because it gives a lighter colored extract, fewer waxes and resins, and retains significantly more volatile oils compared to supercritical CO 2 extracts; however, without the proper equipment rated for the extreme pressures, creating quality CO 2 extracts is incredibly difficult.
Isopropyl Alcohol
Isopropyl alcohol is a commonly used solvent for creating cannabis extractions using a ‘quick wash’ method. Where hexane is not water soluble, isopropyl alcohol is highly water soluble and will dissolve undesired plant materials (chlorophylls and waxes) along with the sought after cannabinoids.
In order to eliminate plant waxes from the isopropyl concentrate solution, a quick wash method is used as opposed to soaking (which is with non-water soluble solvents like hexane)
Although the isopropyl method receives great reviews from patients and tasters, it takes significantly longer to properly purge isopropyl alcohol extracted concentrates due to the solubility in water.
Butane & Propane
The most commonly used solvent in cannabis extraction is butane; however, a mixture of butane and propane has recently become very common as well. These solvents are nontoxic, non-polar and they dissolve oils very efficiently without creating other unwanted byproducts. Butane and propane dissolve all cannabinoids and terpenes (aromatics) with great effectiveness while preserving the integrity of the delicate cannabinoids.
These solvents are cost effective, meaning large amounts of money are not spent on supplies for extraction, but instead on growing quality cannabis to be extracted. Thanks to their lower than room temperature boiling points, butane and propane are able to be ‘purged’ from a concentrate extraction. Note, hydrocarbon extraction is dangerous and should only be done in a proper lab setting.
Hexane
Like butane, hexane is a solvent that can be used for cannabis extractions. Some interesting information: hexane is completely insoluble in water, it boils at a higher temperature than butane, and is extremely flammable and potentially explosive. Although the general process for hexane extraction is similar to that of butane extraction, it requires significantly more care due to the fact that hexane is considerably more toxic.
