Essential Oils, a definition

Essential oils are aromatic essences that humans extract from plants or plant parts. Properly speaking, these aromatic substances are volatile oils.

You can experience volatile oils first hand by smelling the liquids that gush from a citrus peel when you tear it, or inhale the spicy scent of seeds like cardamom, or flowers like clove bud.

What we call “oils” actually start out as natural products of the plants themselves.  Oils or volatile substances are held in the plant’s storage cells for self-defense against predators or diseases.  At harvest time, humans collect the plant parts required for a particular processing mechanism such as a still.  In the process of distillation, the plant part’s volatile oils are separated from the plant’s biomass and collected as the product of this process.  A concentrate of the volatile oils is obtained which we call “essential oils”.

Only a few of the plants of the world, about one-tenth of them, have these aromatic essences which humans desire for fragrance or for flavoring products.

In aromatherapy, essential oils are pleasant and therapeutic odors

In aromatherapy, essential oils are a main source of pleasant and therapeutic odors.  Essential oils are volatile and are thus easily inhaled.  A common route of administration, inhalation of any odorant is a natural response to stimulus.  Our sense of smell and memory relates our experiences to earlier history when humans burned plant parts as incense, to perfume or add fragrance.

In another post, the process of distillation is explained, including what a still looks like and its history.