Essential oils are also known as Ethereal or Volatile oils. They are odoriferous bodies of an oily nature derived from natural resources. In India pure natural essential oils are produced. Essential oils are produced in various internal and external glands of certain flowers, leaves, barks, wood and roots. Chemically these oils are mixtures of natural products from nature and other aromatic compounds.
“Aromatic” does not have the usual chemical meaning in the essential oil business. An aromatic chemical in this case, is any compound that has specific, useful odour.
There are several different ways to extract essential oils, and all require elaborate equipment. As you will see most of the extraction techniques are based on the fact that the majority of essential oils mix with oils, fats, alcohol, and certain solvents, but not with water. Some methods are more suitable for certain plants than others, depending on the plant's chemical make-up.
Distillation is the process used for the Manufacturing of Pure Natural Essential Oils in India. Most of the essential oils are extracted from plants through steam distillation. Freshly picked plants are suspended over boiling water, and the steam pulls the oils out of the plant, bushes, trees, flowers, roots etc. The steam rises, is captured in a vessel, and is pushed along tubing. Then the steam is rapidly cooled, causing it to condense back into water. Since water and essential oils do not mix, the two separate, and the essential oil is collected.
Carbon di oxide is a new method of extracting essential oils. This is one of the most interesting processes, but this is very expensive. The delightful result is an essential oil scent that is very close to that of the plant itself. Use of carbon di oxide method for manufacturing of Pure Natural Essential Oils in India is high in demand.
Expression is one of the most direct method of manufacturing essential oils in India. In this process plants flesh, seed, roots and skin are pressed. The process is similar to that used to obtain olive oil. This technique is used mostly with citrus peels, such as orange, lemon, lime, or grapefruit, because the oil in their peels is easily pressed out.
One of the best method but now a days it has been used very rarely in India, it is a long and complicated process that has become very expensive. Effleurage is a process where blossoms are set on sheets of warm fat that absorb the oil from the flowers. Originally animal fat or lard was used at the place of sheets, but now vegetable fats are more common. Once the essential oil has been incorporated into the fat, the "exhausted" flowers are removed and replaced with fresh ones. The process is repeated several times until the fat is infused with fragrance. Then the fat is separated out with solvents, leaving just the essential oil.