A science of the distillation of essential oil
While there is a science to the distillation of essential oils, it is also an art. Distillers not only rely on years of experience, they also employ modern technologies and techniques.
The most common method of extracting essential oils is a low-heat steam distillation process. In this process, pressurized steam is circulated through plant material. The essential oils are liberated from the plant and carried away by the steam. When the steam cools, the water and oils naturally separate and the oil is collected. To ensure the highest quality oil extract with the correct chemical composition, the temperature and pressure must be closely monitored. Too little heat or pressure and the oil will not release; too much, and the oil’s composition and potency will be affected.
Compression, in which plant parts are pressed to squeeze out the essential oil, is another common method of distillation. Many citrus oils are expressed in this manner.
– Courtesy of doTerra