THC extraction methods are utilized to separate parts of the cannabis plant for various products. The cannabis plant can be used for its plant material or extracts that have various beneficial chemicals. Extraction is used specifically to isolate and get the desired compounds. Cannabis has approximately 113 cannabinoids that include CBD (cannabidiol) and THC (tetrahydrocannabinol). THC extraction can also be used to make a single product with cannabis compounds.
If studying THC extraction methods, remember that extraction is a science, chemistry, not some sort of cooking. The use of analytical skills, proper lab equipment and proper safety protocols is critical in extraction. The use of various methods and solvents for some of these processes means that the company and people doing the extraction does not want to be caught in a dangerous situation. The extraction process needs to be done properly and the product tested to make sure it is safe for all.
Alcohol Extraction
Solvents are often used in cannabis extraction. This particular process uses alcohol. The cannabis is put into the alcohol (often ethanol, which is high proof) to soak and then the plant material is taken out. The liquid left behind is filtered and the remaining alcohol removed through evaporation. The alcohol can dissolve molecules such as chlorophyll which if left in can leave a distinct and often unpleasant bitter flavor in the product.
Alcohol extraction is a fairly simple process, but temperatures need to be controlled especially in the evaporation portion of the method. It takes time and care as ethanol is very flammable. There will not be any toxic residue in the final product due to the use of alcohol and it is great for extracting cannabinoids and terpenoids.
The types of companies that may use this inexpensive process may be smaller start-ups along with ones that are focused on oil, tinctures, creams, and distillates. Companies that are aiming to be environmentally friendly may use it as well as its green-friendly when used with a closed-loop system.
C02 THC Extraction
While many extraction processes use solvents, this one uses carbon dioxide. It uses high pressure combined with heat to make the CO2 supercritical, it is liquid and gas at the same time. The equipment needed is higher priced than alcohol extraction, but you get higher yields and save more of the product. Specific extracts can be targeted using various temperatures, pressure or runtimes.
Once the compounds have been extracted then the supercritical CO2 goes into a condenser and is turned into liquid so it can be reused. This is economical and has little waste compared to some other extraction methods. Any residual CO2 evaporates so there is no solvent present in the end product.
The types of companies doing this type of extraction are those with bigger budgets and making vape and capsule oil, waxes, shatter, and other concentrates. They may also be making distillates as well. It is cost-effective when used on a large scale and a good method for bulk processing.
Butane or Propane Extraction
This first part of this process can use butane for extraction, and it creates butane hash oil (BHC). The process puts cannabis and liquid butane in a pressurized and heated system. The next steps are evaporation under a vacuum to get rid of the solvent. The butane goes from liquid to gas for easy removal. The extraction allows the production of shatter which has THC, CBD and often terpenes. Shatter is the hard version of BHC.
Some safety issues need to be considered when dealing with this type of THC extraction. One is that butane is flammable so managing temperature and the butane itself is important. Circulators are also recommended to recycle the butane. The end product needs to be tested to make sure butane is completely gone and safe for use. While butane or propane is not the safest of extraction methods, it is one of the most popular as it needs little equipment and has a low overall cost. You get a similar product as you would with CO2 extraction with less expense.
This method can also be done by substituting propane in place of the butane. This will make propane hash oil (PHO). It is the same process with a different solvent. The difference for propane is that pressure keeps the propane liquified and the extraction is done at a lower temperature. It is the same steps but adjusts the variable of pressure and temperature to produce a different extract. The two extracts can be combined for a wider chemical profile.
This is a popular way to do extraction for many companies. It is economical and flexible. Products do not need a lot of post-processing. These companies must be big enough to pay for significant safety measures as the solvents are extremely flammable.
Solvent-Free Extractions
Along with oils and shatter, there are also THC extracts such as kief. This extract is taken from the cannabis buds through grinding and sieving rather than solvents. These crystal formations are part of the trichomes of plants. These are very bitter and strong-smelling but when taken from the plant it looks like a powder. It can be used to heighten potency or can be taken on their own.
Old school hash, hashish, is also solvent-free. The goal with this is to separate the trichomes from the plant and then make hash. This can be done through a method of freezing the plant, so they fall off and are made in the block. The other way is to use ice-cold water to separate them.
Along with kief and hash, rosin can be extracted as well. This product comes from buds and is a sappy consistency. Heat and pressure are applied to extract the material. There will be no risk of having residual solvents and is easy to do. A heat press squeezes the material and then the extract is taken off.
This method of extraction is a little more complicated but can create different products giving a company item flexibility. Companies producing hash, rosin, resin, and product for dabbing will prefer this way of production as they can get popular old school products that the market demands.
Final Thoughts
The cannabis market is growing and changing, companies doing THC extraction are going to become more prevalent. Some places are enhancing and improving equipment for safer extraction along with industry experts who are working to improve the extraction process overall.