Before we go any further in this
book, we should clarify what we mean when we talk about essential oils. We’ve
said a lot about aromatherapy, including defining it, and we’ve mentioned
essential oils, but haven’t said exactly what they are.
Most plants contain oil
in their leaves and other parts. These oils can be extracted by various methods
and breathed in or applied to the skin to perform actions on the physical,
psychological, or emotional aspects of a person. So in all of our talk about
aromatherapy, the agents that practitioners use are the essential oils; things
that Mother Nature has provided. The essential oils are the material used in
aromatherapy, so that is why the words are sometimes used interchangeably.
Extraction refers to how the essential oil are taken out of plant material. These materials include flowers,
leaves, stems, roots, bark, basically all parts of the plant.
Each plant is
different, however, so essential oils may be stored in the flowers of one, and
the leaves of another. Sometimes the entire plant is used. It varies from
species to species.
Most essential oils are extracted
from the host plant by a process known as distillation. In their most basic
form, distillers use steam that is forced through the plant material at very
high pressure. We’ve already talked about some ancient distillation and the
basic method hasn’t changed, although the actual tools have. Today the still
itself is a steel, glass, or copper container and most likely can hold a lot
more plants. Personal home units are much smaller, more on this subject later.
The purpose of injecting steam
into it is to heat the plants. When they cool off water from the steam sinks to
the bottom cooling chamber and the essential oils float on top to be harvested.
The remaining water is floral water another useful product. In fact it may be
preferable to the essential oil if you’re treating a child. Many aromatherapy
experts believe that distillation is the best way of separating the oil from
the plant, although there are some other methods.
Cold pressing removes the oils from citrus fruit. You’ve
probably noticed that pressure on their skin can produce a bit of oil, so
extraction is doing the same thing on a larger scale with a lot more pressure.
In this method the fruit rolls over sharp objects protruding from a trough like
receptacle. The objects pierce the tiny pouches in the skin which contain the
essential oil. Then the fruit, pulp and all, is squeezed with a great deal of
pressure. The oil rises to the top of the juice and then is spun in a
centrifuge to remove it.
