Since the scientific composition of each plant differs, several methods for extracting oils from their plants have been developed. Below is a list of the different processes.
Steam Distillation: This is the most common method. In this process, a plant is placed in a receptacle over heated water. As steam forms, it passes through the plant and the “essential compounds” vaporize and condense back into a liquid.
Hydrosols: These are the by-products of the distillation process. They contain the water-soluble constituents of the plant and retain a small amount of essential oil.
Expression/Cold Pressed: A method of extraction specific to citrus essential oils. The process involves a prodding, pricking, sticking action to release the oil.
Solvent: Used for plants that are too fragile to be distilled. Solvent extraction is the use of solvents, such as petroleum ether, methanol or ethanol, to extract the scented material from the plant. The solvent will also pull out the chlorophyll and other plant tissue, resulting in a highly colored or thick extract. The first product made via solvent extraction is known as concrete. A concrete is then mixed with alcohol, which serves to extract the aromatic principle of the material. The final product is known as an absolute.
CO2: Oils are extracted by pressurizing carbon dioxide until it becomes a liquid. The liquid carbon dioxide acts as a solvent on the natural plant matter and the essential oil content dissolves into the liquid CO2. After the CO2 is brought back to natural pressurization, it evaporates back into gas and only the resulting oil remains.
All of our oils are either steam distilled or cold pressed. Some oils like Sweet Orange or Lime can only be extracted from the peel instead of the leaves or flowers, which is why they’re cold pressed. Vanilla is a little different in that there’s no way to steam distill or express the oil. It’s made more like an infusion using natural coconut oil, but is still a pure oil.