Supercritical being a much stronger solvent than subcritical CO2, allows for faster and more complete extractions. This means the lighter oils as well as the not-so-desirable higher molecular weight materials (like waxes, paraffins, lipids and resins) are extracted. These fatty waxes, etc. will then need to be removed from the extract by a process called winterization (described below).
The advantage of subcritical over supercritical is that the extracted oil is pure, free of fats, waxes, and lipids so less post processing work, if any, is required. The purer oil doesn’t need to be further refined and can be used just as it is in vape pens, edibles, and other products. Subcritical oil is full of terpenes (smell) and flavonoids (taste) which are proving very popular among cannabis consumers. Subcritical extractions take longer than supercritical, but with the new Apeks Duplex system that is no longer the case. This system — optimized for fast subcritical extractions — extracts 1 pound in 20 minutes, which is comparable to a supercritical extraction.
Because all Apeks Mid-Range and High Production Series systems extract at both subcritical and supercritical parameters, processors can perform a “fractional extraction” by first extracting at lower temperatures and pressures to remove the lighter, temperature-sensitive volatile oils, and then subsequently extract the same material at a higher pressure and temperature to extract the remaining denser, heavier oils (waxes, etc.).