Essential Oil Basics
Essential oils are the highly concentrated, volatile, aromatic essences of plants. Scientists agree that essential oils may perform more than one function in living plants. In some cases they seem to be a part of the plant's immune system. In other cases they may simply be end-products of metabolism. Essential oils contain hundreds of organic constituents, including hormones, vitamins and other natural elements that work on many levels. They are 75 to 100 times more concentrated than the oils in dried herbs.
Not all Oils are Created Equal
Some plants, like rose and jasmine, contain very little essential oil. Their important aromatic properties are extracted using a chemical solvent. The end product, known as an absolute, contains essential oil along with other plant constituents. Though not a true essential oil, absolutes are commonly used for fragrancing cosmetic products like fine perfumes.
There are also significant differences between synthetic fragrance oils and pure essential oils. Synthetic fragrance oils are produced by blending aromatic chemicals primarily derived from coal tar. These oils may duplicate the smell of the pure botanical, but the complex chemical components of each essential oil created in nature determine its true aromatic benefits. While synthetic fragrance oils are not suitable for aromatherapy, they add an approximation of the natural scent to crafts, potpourri, soap and perfume at a fraction of the cost.
Aromatherapy practitioners need pure essential oils of the highest quality. Important criteria to consider when selecting essential oils include the following: 100% pure and natural, country of origin, growing season, extraction method (e.g., distillation, expression), plant part used and the reputation of the company providing the oils.
Gems of Nature
Pure essential oils, like precious jewelry or fine wine, are gems of nature -- the quintessential life force of aromatic plants, sometimes called the "soul" of the plant. People who truly appreciate the qualities of pure essential oils consider each drop a precious jewel to be savored, enjoyed and protected.
Essential oils absorb into the fluid surrounding the cells beneath the skin's surface for a variety of effects including deep cleansing, nourishing, rejuvenating and balancing. Essential oils also diffuse into the air to provide olfactory benefits.
Extraction of Essential Oils
To extract essential oils in the most effective manner while preserving their therapeutic benefits, they are either distilled or expressed. The two methods are briefly explained below.
Pure essential oils are most commonly extracted from plants through the process of steam distillation. In this process, steam is introduced into a distillation chamber which contains the plant material. The steam breaks down the plant tissue, causing it to release its essential oil in a vaporized form. The vaporized essences, along with the steam and other substances, pass into a pipe through cooling tanks. The vapors return to liquid form and are separated from the water and captured as pure essential plant oil.
Expression, also known as cold pressing, is done exclusively with citrus oils. In this method, the oil-containing outer layer of the fruit is pressed and filtered to yield pure essential oil.
It takes 50 pounds of eucalyptus, 150 pounds of lavender, 500 pounds of rosemary, 1,000 pounds of jasmine and over 2,000 pounds of rose to make a single pound of essential oil! The price of each essential oil is directly related to the amount of plant material needed for distillation.
*Copied from Aura Cacia's own information page: http://www.auracacia.com/auracacia/aclearn/ar_basics.html