All about Essential Oils
An Essential oil is the natural substance that is extracted from flowers, herbs, grasses, shrubs, trees, citrus, resins and spices. Now days this is USUALLY accomplished via a process called steam distillation. Modern advances in machinery have made this a more economical and less time-consuming way to extract the essences of these plant substances.
The quality of the oil is dependent upon the method of extraction. Cold Pressed - is where heat is reduced and minimized throughout the batching of the raw material. This helps the oil maintain its original state, constituents, and depth. Temperatures are rigorously controlled to ensure that it does not exceed 80-90 degrees Fahrenheit. Although not a practical method of extraction for all vegetable oils on the market, it is highly regarded as the extraction method of choice.
Expeller Pressed - is a natural, mechanical extraction and processing of oils where a small amount of heat is produced simply through the frictional heat created by hydraulic presses. This is usually around 120-200 degrees Fahrenheit and makes the oil suitable and economical as a base for cosmetics because of its fairly undisturbed molecular state. It also makes a fine food grade oil.
Refined - A fully processed oil where it has been exposed to all methods of refinement including a flash fluctuation in temperature as high as 450 degrees and winterization as low as -30 degrees, deodorization, which removes the heavy and often unsettling odor in oil, and finally bleaching, where natural clays and other mediums are used to alter or remove an oils color, and scent. This makes for an economical oil in cosmetics and body care products, but it is not the healthiest as a food grade oil.
Partially Refined - A process where only some of the methods available are employed to produce a manufactured oil. Only one or two of the three available methods are used in a partially refined oil. These include, but are not limited to; deodorization, winterization and natural bleaching. These methods are used for oils which have been known historically to go rancid quickly, and they are also used to further stabilize an oil or remove its heavy odor and deep color.
Unrefined - A process of mechanical extraction and screen filtering where no additional refining process has taken place. This ensures the finest quality product and makes the oil the most exquisite for food and cosmetic preparation. The unrefined process helps oil retain a rich, strong flavor and color that is true to its natural state. Unrefined oils are always darker in color and richer in scent.
Before the onset of machinery, the method of making EO's was time very consuming and involved encouraging the plant material to disintegrate. If you are going to hand make you own EO, this is the method to use. It also is called cold press. In this method, as the plant material disintegrates it leaves its "essence", in the form of moisture, in a small amount of carrier oil. This essence, or liquid, is drawn out and preserved in the oil as the plant body or fiber basically "rots", away. Some manufacturers still use this method for a few of their oils, although, they have machinery to speed the process along.
No matter how the extraction is forced to occur, or if it is in a factory or your home, the end product is called an essential oil. Your supplier of EO's will most generally list their method of extraction in the product description. While the commercial methods generally make for a fairly uniform fragrance potency, any home made EO will not (usually) be as strong as the commercial methods, simply due to efficiency of machines. Simply increasing the number of drops in your recipe will compensate for the lower strength of your fragrance.
If you want to try making your own EO, you will need to have a good carrier oil on hand. You should choose one that has a long (natural) shelf life and as little of its own odor as possible. You should not use "just any old" cooking oil. I like a half jojoba and half apricot kernel oil blend myself, but you can experiment and find your own favorite.
You'll also need about 4 cups of whatever you are wanting to process. Make sure it is FRESH, not dried. I suggest lavender because it is readily available in the summer and I love it, but you choose whatever you like best. You can choose from herbs, spices, citrus peels, grasses, shrubs, trees, or resins. You need only to make sure you use the correct part of your choice. For instance; use the buds for lavender, the leaves for bay laurel, the peel for citrus, and the wood and plant parts of cedarwood. Do not use anything treated with pesticides. If you are unsure, wash and DRY before using. Make sure that you remove all moisture from your choice of material before you use it. If not, you will be likely to create mold instead of a FO.
Also choose a meaty material, one with little water content. If there is mostly water in your choice it will not mix well and will not produce a quality FO.
Take your herbs or flowers, or whatever you chose, and (with gloved hands) gently bruise them. This makes them open up. Now place the bruised material in a jar or container. Pour aprox. 1/2 cup of your carrier oil over the material you chose. Use as little oil as possible, but make sure the there is sufficient oil, as you will not be reopening the jar until it is completed. After the oil is added, close the jar and shake for at least one minute. This really starts the bleeding of the substance into the oil. You must now find a nice dark spot in the house, and leave your jar there. Once a week, take your jar out and shake it for a minute or two, then return it to its dark place. After a month, remove it and strain the oil through a cheesecloth. Everything but the clear, essential oil you made is thrown out. Store the oil in a dark, glass bottle. As long as you keep it in a cool, dark environment, it will remain good for 12-18 months.
While I have garnered my information from years of reading and research, I will be digging out the books and posting some for reference material the next time I'm on here. Until then, I'm going to go bruise some grapefruit peels and find a bottle, cuz all this remembering how has made me miss doing my own!