While many hemp and CBD companies boast about their supercritical CO2 extractions, supercritical extraction is actually just one approach to CO2 extraction, and may produce inferior results. Other approaches include subcritical CO2 extractions, which use a lower temperature and a lower pressure, and ‘mid-critical' extractions, which use temperatures and pressures falling between those used in subcritical and supercritical extractions.
Subcritical CO2 extraction takes more time and produces a smaller yield than supercritical extraction. This procedure, however, is better able to retain many of the important oils, terpenes, and other sensitive chemicals within the plant. Supercritical extraction, on the other hand, is a high-pressure, high-heat procedure that harms most of the plant’s terpenes and heat-sensitive chemicals. The advantage of supercritical extraction is its ability to extract much bigger molecules, such as lipids (omega-3 and omega-6 fatty acids), chlorophyll, and waxes.
A genuinely full-spectrum CO2 extract consists of an initial subcritical extraction, a secondary supercritical extraction from the same plant material, and the homogenization of the two resulting oil extracts into one. In the vital oil industry, an extract derived from this specific process is described as a ‘CO2 Total.’