Cannabis Oil Extraction
There are a number of ways of extracting CBD from any of these varieties of cannabis. If the plant you start with contains only CBD (like industrial hemp or a high-CBD cannabis strain); there are multiple extraction methods which are very simple and require little equipment.
The supercritical (or subcritical) CO2 method uses carbon dioxide under high pressure and extremely low temperatures to isolate, preserve, and maintain the purity of the medicinal oil. Carbon Dioxide (CO2) is a unique molecule that can function as any state of matter— solid, liquid, or gas— depending on the pressure and temperature it is kept under. Because variables like pressure and temperature have to be kept very specific in a CO2 extraction, this extraction method is usually done with a piece of equipment called a ‘closed-loop extractor’. This machine has three chambers: the first chamber holds solid, pressurized CO2 (commonly known as ‘dry ice’), the second chamber contains dry plant material and the third chamber separates the finished product. When performing the extraction, the solid CO2 from the first chamber is pumped into the second with the plant material. This second chamber is kept at a specific pressure and temperature which causes the CO2 to behave more like a liquid (although it’s actually somewhere between a liquid and gas in this state, referred to as supercritical CO2) so that it runs through the plant material and extracts chemicals and flavours, much like in the liquid solvent process. Then, the C02-cannabinoid mixture is pumped into a third chamber where it is kept at an even lower pressure and higher temperature so that the C02 gas rises to the top of the chamber while the oils containing chemicals and flavours from the plant material fall to the bottom to be collected for consumption.
High-grade grain alcohol can be used to create high-quality cannabis oil appropriate for vape pen cartridges and other products. In this method, plant material like flowers and trim are put into a container. Liquid solvent (usually butane, isopropyl alcohol, hexane, or ethanol) is run through the plant matter to strip it of cannabinoids and flavors and transfer them into the liquid. Then, the liquid is evaporated away from this mixture to leave only concentrated chemicals and flavors in the form of an oil.
Concentrate can be made using either Olive or Coconut oil. This is the simplest and safest extraction method. First, raw plant material must be decarboxylated, or heated to a specific temperature for a certain length of time to activate the chemicals in the plant. Plant material is then added to olive oil and heated to 100°C for 1-2 hours to extract the cannabinoids. With this method, the olive oil cannot be evaporated away after the process, so users must consume much higher quantities of this type of extracted oil than the highly-concentrated oil produced by other methods. Infused olive oil is also highly perishable, and so must be stored in cold, dark place. This makes it unviable for commercial CBD producers, but a simple, safe, and inexpensive option for individual enthusiasts.