CBD extraction method #3 – Carbon Dioxide
CO2 cannabis extraction uses equipment able to pressurize carbon dioxide into non-gaseous states. When pressurized, the CO2 is able to pull CBD and other cannabis constituents from plants in a highly efficient, safe manner.
Speaking in layman’s terms, compressing, cooling, and sometimes freezing CO2 allows it to act like the hydrocarbon solvents used in method #1. Once the CO2 has pulled the cannabinoids and essential oils from the hemp plant, the thick, sludgy mixture (Check out this article from producer Dutch Passion for pictures), is usually passed through a separator, which breaks it down into requisite parts.
This process allows manufacturers to be super-accurate in creating their CBD oils, combining different elements of cannabis, or leaving the CBD as a pure isolate. All the good stuff is then collected while the CO2 goes through a condenser and is turned back into a liquid for reuse.
Depending on the pressure and heat used, CO2 extraction can fall into several categories. The main two are supercritical and subcritical extraction:
- Supercritical extraction is in many ways the current standard for commercial CBD oil production. Thanks to its ability to produce safe CBD in a relatively quick time, it may be the most regularly used extraction method in the US. At supercritical levels, CO2 hovers halfway between a liquid and gas, simultaneously holding properties from each state. Manufacturers are able to use CO2 in this state to produce highly potent CBD.
- Subcritical extraction uses CO2 at lower temperatures and pressures. While this method usually takes longer and produces a smaller yield, it tends to extract less unwanted byproducts and larger molecules such as chlorophyll—as well as being less likely to damage delicate terpenes.While supercritical has been considered the optimum extraction within the industry for some time, subcritical is increasing in popularity. According to industry insiders CannabisTech, “as more emphasis is placed on full-spectrum plant products and the role of terpenes in cannabis products, subcritical CO2 extractions have challenged common thought and practice.”
How does this method affect CBD oil quality?
Giving your dog CBD oil extracted via carbon dioxide is a great way to provide extra insurance against unwanted extraction byproducts, or contaminants in oil as a result of production. Even if excess CO2 were to somehow find its way into your dog’s oil, the effect would be no different to them consuming a small amount of soda, or other carbonated products.
Using CO2-extracted oil also safeguard quality in the sense that the method is cost-prohibitive, meaning that it tends to only be used by serious market players. For those manufacturers, the ability to alter CO2 pressure and temperature allows them to be selective in the compounds they extract from cannabis.