CO2 extracts are categorized in two ways, as “select” and “total”:
- Extracted at lower pressures, Select extracts contain only the volatile compounds that are CO2 soluble. Waxes, resins, and compounds that lend color remain in the plant material. Selects are often thick but pourable, with an appearance similar to steam-distilled essential oils, though some of the volatile compounds they contain will not be found in a steam-distilled version of the oil.
- A Total CO2 extract, on the other hand, does contain both volatile and non-volatile CO2 soluble compounds. This means total extracts tend to be thick like paste, though they will solubilize in vegetable oils with little or no warming necessary. More similar to the plant themselves, totals are extracted at higher pressure and include some of the plant waxes and resins.
by Marianne Griffeth ©2013