When we talk about essential oils, most people only think of lavender in a diffuser, or even the strong smell of patchouli from a dubious tarot card reader... Yet, they are part of our daily lives without even realizing it (essential oils, not dubious tarot card readers)!
Here is a very simplified explanation: Essential oils are, at their core, plant extracts. Most essential oils are made by distillation, a process in which plant parts are exposed to heat and steam. The plant's fragrant molecules ("essence") are then carried in this steam to tubes that are cooler than the steam, causing condensation (return to liquid state). Like in cooking, water and oil separate in the final container: the product at the bottom is called "hydrosol," and the top part, the essential oils. Distillation is the same process used to make many alcohols, such as whisky and brandy.
"The Simple Still or The Still of Pharmacists, Liquorists, and Perfumers" Source: The Wonders of Industry or, Description of the Main Modern Industries / by Louis Figuier. - Paris: Furne, Jouvet, [1873-1877]
Other processes are often used, depending on the plant involved, such as mechanical extraction (pressing orange peels, for example), solvent extraction, CO2 extraction, as well as enfleurage (soaking and macerating plants in specific oils).
Ok, but how are these oils so useful?
In aromatherapy, of course, they are used pure or diluted, and can be found in diffusers, sprays, and massage oils... But they are also found, more subtly, in cooking, household products, room fragrances, and health products!
For example, in the traditional "candy canes" of the holiday season, the mint flavor usually comes from derivatives of peppermint or spearmint essential oils! Some well-known lozenges contain derivatives of mint and eucalyptus oil, just like the good old ointments used on the feet, throat, and back for colds and flu.
Many room fragrance sprays or odor eliminators also contain various essential oils or derivatives thereof, mostly floral or fruity. Some essential oils are also used as pesticides and insect repellents for years. There are even essential oils specifically used in cooking for biscuits or cakes, as well as for beverages, such as soft drinks.
Essential oils are not only used for their scent or flavor. Some essential oils are preferred for their chemical properties or physical effects. For example, peppermint has a numbing effect when used on mucous membranes (mouth, throat) and skin, providing a sensation of freshness, making it useful for throat lozenges and toothpaste for sensitive teeth.
