Extraction
by Solvents
This method is most often employed for the fragility
of floral oils. A solvent compound or mixture is poured
over petals and buds and the essential oil dissolves
itself into the lap of the solvent. Solvents may vary
from the newer sophisticated methods of carbon dioxide
or the environmentally hazardous liquid butane, to crude
applications of alcohol, to more toxic elements such
as ether, hexane, benzene and other petroleum based
compounds. The primary advantage to this method is that
a low, uniformed temperature range and low pressure,
is employed and maintained, allowing the flower’s
signature fragrance to be captured, which heat can alter
through injuring fragile components.
The result is a semi-solid material referred to as a
‘Concrete’. Often times a ‘concrete’
is sought after in perfumery. It will contain waxes
and residues which must be filtered away and purified
with the help of alcohol washing, freezing and a low,
gentle vacuuming. This will evolve into uncovering what
we know to be an ‘Absolute’. Their colors
are rich and their consistency, dependent on the filtering,
range from a thickened cream to resinous, to having
the ability to crystallize, or even become semi-solid
at lower temperatures.
The primary disadvantage to an absolute is that chemicals
incorporated into the extraction may remain present
in the oil, especially that of ethyl alcohol, usually
at a 1-2% range. Not only does this open the doorway
wide to the possibility of skin sensitization it as
well makes adulteration of the oil more accessible and
less discernible by an untrained nose. Many Therapists
choose not to incorporate Absolutes into their therapies
as a result.
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