CO2 extracts vary entirely by source material. The general quality is 'truer to nature' — less cooked, less artifact-laden than distilled oils. Rose CO2 is richer and more complete than rose otto; vanilla CO2 is deeper and more complex than vanilla absolute. The method preserves compounds that heat and solvents destroy or alter.
Evolution over time
Immediately
Immediately
Varies by material — generally fresher and more naturalistic than distilled equivalent
After a few hours
After a few hours
Depends on source material
After a few days
After a few days
Depends on source material — generally good tenacity due to preserved heavier fractions
The Full Story
CO2 extraction (supercritical fluid extraction) is a method, not a fragrance note. It uses carbon dioxide at high pressure (above 73 atm) and moderate temperature (31+ degrees C), where CO2 enters a supercritical state — neither gas nor liquid — becoming an excellent solvent for volatile organic compounds.
The advantage over steam distillation is that CO2 extraction operates at lower temperatures, preserving heat-sensitive compounds that distillation destroys. The advantage over solvent extraction (hexane, ethanol) is that CO2 leaves no solvent residue — when pressure is released, CO2 simply evaporates as gas.
CO2 extracts often smell more 'true to nature' than distilled oils because they retain compounds lost during heating. Rose CO2, for example, preserves phenylethyl alcohol (the dominant molecule in rose scent) that is largely lost during steam distillation. Ginger CO2 retains more of the fresh, zingy character of raw ginger than the cooked-smelling distilled oil.
The supercritical point of CO2 (31.1 degrees C and 73.8 atm) was first described by Thomas Andrews in 1869. The technology only became commercially viable for natural products extraction in the 1980s, making it one of the newest extraction methods in a perfumery tradition that dates back to ancient Egypt.
Extraction & Chemistry
Extraction method: Supercritical CO2 extraction uses carbon dioxide above its critical point (31.1 degrees C, 73.8 atm) as a solvent. The raw material is loaded into a pressure vessel, supercritical CO2 is pumped through, dissolving volatile and semi-volatile compounds. Pressure is then released, CO2 evaporates, and the extract remains. Two main types: 'select' extracts (lower pressure, more volatile compounds) and 'total' extracts (higher pressure, including waxes and heavier compounds).
Molecular Formula
N/A (extraction method)
CAS Number
N/A (extraction method, not single material)
Botanical Name
N/A (extraction technology category)
IFRA Status
No known restrictions
Synonyms
carbon dioxide extracts
Physical Properties
Odor Strength
Medium
Appearance
Colorless to pale yellow clear liquid
In Perfumery
CO2 extraction is a technology, not a fragrance building block. It produces extracts (called 'CO2 selects' or 'CO2 totals' depending on pressure) that are used alongside traditional essential oils and absolutes. Particularly valuable for spice materials (black pepper, ginger, cardamom CO2), where the method preserves fresh-spicy top notes lost in distillation. Also used for delicate florals, vanilla, and coffee.
