Essential oils, also called volatile or ethereal oils, are aromatic extracts from plants. Essential oils have been used since ancient times for cosmetic, medicinal, and culinary purposes. They may be extracted from the roots, flowers, leaves, seeds, bark, fruits, peel, wood, or the entire plant. If a plant has an aromatic part (such as valerian root, sage leaves, orange flowers, and dill seeds), then it contains at least one essential oil.
Essential oils are highly concentrated. In order to manufacture 15 ml of rose oil, nearly 30,000 roses are needed. Nearly three thousand different essential oils are currently known. Oil composition varies greatly even among plant specimens of a single species. Factors such as climate, growing conditions, and harvest time have significant impacts on the final product.
Essential oils can be generated through a variety of processes. Most of these processes fall under three categories: distillation, expression, and solvent extraction. The most common methods of extraction are steam distillation and expression.
Distillation involves the application of heat and water or steam to the plant. The process converts essential oils to a vapor and then condenses them back into liquid form.
Mechanical expression is “cold pressing” the plant material under high force. No heat is applied.
Solvent extraction is a technique more often used by perfumers for delicate plants. Hexane is used to dissolve the oil and plant resins and waxes. The solvent is vaporized, leaving behind a resinoid. Alcohol is applied to the resinoid to remove the essential oils, and then evaporates. An absolute oil is the final product. Absolute oils are often very expensive, but the process more accurately captures the original fragrance of the plant than other techniques.
Essential Oils List –