“Aromatherapy is… the skilled and controlled use of essential oils for physical and emotional health and well-being.” Valerie Cooksley
Aromatherapy, also referred to as Essential Oil therapy, can be defined as the art and science of utilizing naturally extracted aromatic essences from plants to balance, harmonize and promote the health of body, mind and spirit. It seeks to unify physiological, psychological and spiritual processes to enhance an individual’s innate healing process.
Products that include synthetic ingredients are frowned upon in holistic aromatherapy. It is important to note that perfume oils also known as fragrance oils (and usually listed as “fragrance” on an ingredient label) are not the same as essential oils. Fragrance oils and perfume oils contain synthetic chemicals and do not provide the therapeutic benefits of essential oils.
An essential oil is a natural product extracted from a single plant type. Not all plants produce essential oils, and in the plants that do, the essential oil may be found in the roots, stems, leaves, flowers, or fruits.
It is important to note that essential oils do not feel oily; they are called “oils” because they contain the oil-soluble chemicals in the plant (usually 100 to 200 chemicals per essential oil). This complex chemistry gives essential oils their therapeutic properties and explains why different essential oils may have overlapping effects.
It is important to know something about how essential oils are extracted because oils from the same plant extracted in different ways can result in very different products.
The two main ways to extract an essential oil from a plant are steam distillation and expression. Newer extraction methods, such as supercritical CO2 extraction, are also becoming more common.
In this method, steam is directed through the plant material. The steam heats the lighter chemicals contained within the plant material. The steam is then reduced through a cooling process. This process produces two products: the essential oil, which contains oil-soluble molecules, and a hydrolat or hydrosol, which contains water-soluble molecules.
Rose water is one of the best known and most widely-used hydrosols worldwide, with many cosmetic and culinary uses. In fact, in the past, rose petals were distilled as much for their hydrosol as their essential oil. Some essential oils, like rose oil (rose otto), smell different from the flowers from which they were obtained because the heat of distillation alters some of the chemicals that gives them their distinctive smell.
Expression is used to extract essential oils from citrus fruits. Expression is the process of grating or scraping the peel of a citrus fruit to release the oils. For example, when zesting a lemon, the scent of lemon rises into the air because the volatile oils have been released from sacs found in the peel.
In the process of essential oil expression, care is taken to capture the oil. Expression does not involve heating; thus, the chemistry of citrus essential oils is not heat-altered and citrus oils smell very similar to the fruits from which they come.
Supercritical C02 Extraction
In supercritical C02 extraction, carbon dioxide is used as a solvent. It is added and eliminated to produce a high-grade extract that is very close to the structure of the natural raw material. C02 extracts are different from distilled oils in that they contain a wider range of the chemical molecules found in the plant material.
You might find essential oils obtained by both distillation and C02 extraction from the same plant species. They would be chemically different; therefore, they may have different therapeutic qualities as well as different safety factors to take into account.