Essential oils aren’t oils. They aren’t greasy, are usually as light as water and quickly evaporate, none of which is true of oils. An essential oil is the essence of a plant, or its personality, the plants life force distilled for use. The fragrance and character of each oil are as individual and unique as a finger print, as are its therapeutic properties and the effects they may have on individuals.
Essential oils are actually volatile, aromatic substances which naturally occur within certain plants. These are what give rose, garlic and all other scented plants their distinctive odours. Approximately 300 essential oils are commercially available, but of these only 50-100 have health giving properties and are suitable for home use and for the aromatherapist.
Not all plants contain essential oils. In those that do the oil, or essence, is contained in highly specialised glands that are present in the foliage, flower, or other plant material.
The chemicals present in essential oils are:
Each of these chemicals has its own properties, and these are imparted to the essential oil when the chemical is present in large quantities. True essential oils may consist of hundreds of specific ingredients (chemical properties). Rose essential oil, for example, contains about 500 constituents, each harmoniously existing within the essential oil. These are the ingredients which give essential oils their aromas and the ability to change our minds, bodies and emotions. The chemicals in the oils unlock the body’s ability to heal.
True essential oils contain the correct ingredients in the correct combinations. Most are non-toxic and are easily assimilated into the body: through the nose and lungs during inhalation and via the skin during massage where they are carried to all parts in the blood. Diluting the oils delays their passage through the body but does not detract from the efficacy of the essential oils. After a treatment the essential oil remains in the body for three to four hours, activating the healing process, which can continue for two to three weeks.
Essential oils are able to influence all aspects of the body’s functions, from tissues to organs, to body fluids and cells as well as the emotional state and the spiritual aspects of the person.
Essential oils are obtained from plants materials by a number of methods, most of which are costly, potentially explosive and best left to professionals. It is virtually impossible to create essential oils at home so DO NOT try.
Most essential oils are produced by distillation or expression. Generally, because of the fragile nature of the raw material, the processing takes place in the country of origin. More robust materials, such as wood bark, and seeds, are sometimes exported for distillation elsewhere. Herbs and flowers can be distilled fresh or dried, and hardier materials such as wood needs to be chipped or even powdered before processing can begin. The citrus oils, which contain their essence in the peel of the fruit, are all expressed (squeezed). Other essential oils are produced by dry, water, or steam distillation.
The commonest method of production is steam distillation. By this method the volatile and water soluble parts are separated from the rest of the plant. The resulting mixture may need to be distilled a second time to remove non-volatile matter.
In the distillation process the plant is placed in a sealed container. Water in a second container is heated to produce steam, which is passed under pressure through the plant material. The steam causes the glands containing the essence to burst, allowing the volatile chemicals to dissolve in the steam. This rises and is taken into a condensing chamber, where it is cooled. As it cools the oil is separated from the water. Floral water is a by-product of distilling, and like essential oil has therapeutic and commercial uses.
A different process, solvent extraction, is favoured for releasing essential oil from more delicate material, such as jasmine flowers. The plant material is washed with a solvent such as alcohol until the essence dissolves. The resulting material is then distilled at a precise temperature to separate the solvent and the aromatic oil. Oil made by this process is known as an absolute.