Essential Oil Extraction Processes - Distillation
Steam Distillation
The majority of essential oils available today are extracted using a steam distillation process. It's the oldest form of essential oil extraction and is believed by many to be the only way oils should be extracted. The process really is quite simple and as long as this extraction process is closely monitored, the steam will remain at a temperature that won't damage the plants.
The desired plant material is placed onto a still. A still is a specialized piece of equipment that is used in the distillation process. It consists of a vessel into which heat is added and a device that is used for cooling. The plant is first placed into the vessel. Next steam is added and passed through the plant. The heat from the steam helps to open the pockets of the plant that contain the plant's aromatic molecules or oils. Once open, the plant releases these aromatic molecules and in this state, the fragrant molecules are able to rise along with the steam
The vapors carrying these molecules travel within a closed system towards the cooling device. Cold water is used to cool the vapors. As they cool, they condense and transform into a liquid state. The liquid is collected in a container and as with any type of oil/water mixture, it separates. The oils float towards the top while the water settles below. From there, it's a simple matter of removing the oils that have been separated. These are the highly condensed, aromatic oils used in aromatherapy
The water is not discarded, however. The water, which also contains the plant's aroma along with the other parts of the plant that are water soluble, are the hydrosols - a milder form of the essential oils. These, too are also used in aromatherapy.
When steam is used, it's created at a pressure higher han that of the atmosphere. The boiling point is above
|