Intro to Essential Oil Chemistry Part 2: Extracting Oils

Everything is chemistry. Every cell, organ, and tissue in the body performs its function using enzymes, receptors, and other proteins, which work together to break down, build up, and rearrange the chemical bonds in biological molecules. Essential oils also operate under the principles of chemistry.

The unique chemical makeup of each essential oil is what gives them the ability to affect the body’s systems. Molecules in essential oils can selectively support the function of subcellular structures that run the processes that keep us alive. By understanding the fundamentals of oil chemistry, you can begin to classify oils by their chemical properties. This will help you learn which oils might have applications in different daily life contexts and how they work.


Essential oils are called “essential” because they are the “essence” of a plant. In the Middle Ages, it was believed that essential oils were essential for life, giving them the moniker that has stuck even to the present day. Modern references define an essential oil as the essence, or extract, that is the source of a plant’s aroma and flavor. For example, peppermint plants smell like peppermint because of the essential oil contained in their leaves and stems. Oranges smell like oranges because of the essential oil contained in the peel. Why do plants produce essential oils?

Essential oils are a critical part of a plant’s immune system. Plants produce essential oils to protect themselves against environmental threats. The parts of a plant with the greatest amount of essential oil are usually the parts with the greatest risk for invasion by microorganisms: the bark, sap, leaves, seeds, and fruit rinds. The compounds found in essential oils have all sorts of biological activities. They are known to protect against environmental threats, soothe the body, and even calm the mind.


While it is important to note that essential oil extraction is unique to every plant, in general, dōTERRA essential oils are extracted using one of three methods: steam distillation, cold press, or solvent extraction.

Steam Distillation is the most common method for collecting essential oils. In steam distillation, water is boiled and the resulting steam passes through the plant material.

The steam carries the essential oil from the plant into a collecting tube, where the steam is cooled and condensed back into water. Because essential oils are lipid soluble (meaning that they mix readily with other oils), they are easily separated from the water.

Cold Press is a method that doesn’t involve heat. Cold press extraction is used exclusively with citrus fruits because it is a way of extracting oil from the outermost layer of the fruit’s peel.

The fruit is passed across sharp rasping cylinders that abrade the surface of the peel to break open small essential oil-containing sacs. Water is then sprayed over the fruit to collect the essential oil. The resulting watery mixture is then filtered and centrifuged to separate the essential oil from the water.

Solvent Extraction can be used on every type of plant material, but is most commonly used on flowers that are too fragile to endure the conditions required for steam distillation.

The plant material is washed with a solvent to dissolve out the fragrant compounds. The resulting mixture is then filtered to remove the plant material, and then the solvent is removed using vacuum distillation. The yield of this process is a thick, waxy material called a “concrete.” The concrete is processed again in a similar fashion but with a different solvent. After another round of vacuum distillation to remove the second solvent, a pure mixture of only absolute remains. Common absolutes extracted by this method are Jasmine and Vanilla.

Hooray! You learned a thing!