What is an Essential Oil?

I started talking a bit about essential oils last week, but got so distracted blathering on about trans fats that I never really discussed them. But then there’s no time like the present is there?

Essential oils are, as the name implies, liquids that constitute the essence of a plant or fruit’s flavor. They’re not actually oil (plant fat), but they’re oil-like, which is to say they’re hydrophobic, or hate water, and are volatile, which means made up of small, light molecules that drift off into the air rather easily (evaporate).

Essential oils are frequently confused with flavored oils, though the process of producing them is completely different. Whereas flavored oils are made by steeping herbs and spices in bottles of olive or vegetable oil, essential oils are isolated from the herbs and spices themselves. Thus, they are much more powerful.

Some plants have quite a lot of essential oil. Lemons, for example, contain so much essential oil that it can simply be pressed out of lemon peels and leaves. Other types of essential oils such as, say, clove oil, have to be distilled. That is, quantities of leaves, fruit, seeds, roots or bark (wherever the oil resides) are placed into vessels and steamed. As the plant matter breaks down the essential oils are liberated and float off, later to condense and be collected as a concentrated liquid (Kentucky moonshine is made the same way). The water that gets mixed in with the oil is easily separated out at the end. This highly aromatic by-product (known as a hydrosol) is often a product in its own right. If you’ve ever wondered where things like rose flower water and orange flower water come from…wonder no longer.