Essential oils are natural health remedies for skin diseases. They are derived from plants by means a few different extraction techniques. They are a concentrated essence of the plant they come from that can be used for healing, aromatherapy, cleaning or relaxation. Extracting essential oils is a delicate process and specific attention has to be paid to ensure that the finished product is potent and free from impurities.
Out of all the methods of extracting essential oils, distillation is the most common and most effective. This is where raw plant materials (leaves, bark, roots, seeds) are placed in a container which steam is able to pass through. This is placed over water which is then heated to create the steam. The heat and steam break down the plant matter, releasing the essential oil, which rises with the steam. The steam travels into a condenser where it cools into water and flows into a separator. In the separator, the oil rises to the top of the water where it can be extracted and bottled. The remaining water has a little of the essential oil and can be used as floral water (also called hydrosol).
Before the technology of distillation was commonly used, people would employ expression as a means of extracting essential oils. This process is still used today to extract citrus oils, olive oil, and a few others. Expression is where the plant matter (an olive or an orange peel, for example) is cold pressed to squeeze the oil from it. This method can be used for oils that would be damaged due to the heat required for the distillation process, but it yields a smaller amount of oil per plant and is therefore less efficient.
Because distillation does require a certain amount of heat to be applied to facilitate the process, many oils that come from flowers need to be derived by means of solvent extraction. They’re too delicate for distillation and don’t contain enough oil to make expression productive. In solvent extraction, a substance such as hexane or supercritical carbon dioxide is used to draw the oil out of the plant, creating a waxy mixture of essential oil and solvent. The oil is then separated from the solvent to yield the final product.