Plant-based essential oils have been used for thousands of years. Essential oils are extracts from certain plants, trees, and fruits. Since plants contain such a small amount of extract, several to many pounds of plants are needed to provide a small bottle of essential oil. The essential oils are then refined and distilled and packaged in containers that help maintain the scent and fragrance. Extracting essential oils has been known for over 5,000 years, according to the National Association for Holistic Aromatherapy. Methods for extracting essential oils have improved over the years. Although the equipment has changed, the basic processes used are still those discovered by our ancestors many thousands of years ago. What follows is a fascinating look at the methods used for extracting aromatherapy essential oils.
- Steam Distillation- The most popular and oldest distillation process. Traditional aromatherapy professionals believe this method is the best way to produce the highest quality extracts. Distillation takes dried or fresh plants and places them onto a grid inside a steam chamber. Steam or water and steam are then applied to the plant products to breakthrough and release the volatile oils. The steam containing the volatile vapor then rises and enters a cooling condenser, where the steam and volatile oils turn from a gas back into a liquid. The essential oils and water are then separated. Most essential oils float on top of the water and are siphoned off. Some essential oils are heavier than water and so separate and create a bottom layer in the chamber, with the water sitting on top of the oil. Clove oil is one such heavier than water oil. The pure essential oils can then be packaged and sold as pure essential oils. The water also contains traces of the essential oils and so is often sold to cosmetic companies for use in their products.
- Water Distillation- Water distillation is another method of distillation, only using liquid water instead of steam. Water distillation is used in extracting essential oils from delicate flowers. Using steam with delicate flowers makes the flowers clump together. This makes it hard for the steam to penetrate the flowers. So the flowers are placed in water and the water is brought to a boil under a vacuum. The reduced pressure decreases the boiling point of the water and allows the temperature to be lower, protecting the delicate oils from overheating. The mixture is allowed to cool and again the essential oils separate from the water. The essential oils are siphoned off to be sold as a pure extract. The water used in this method is also sold. It is marketed as a hydrosol or sweet water. You have probably seen it on the shelves with such names as rose water or lavender water.
- Hydro Diffusion- Another method of steam distillation. With this method, the steam is introduced from the top of the still instead of from the bottom. The condensed oils and water are collected below the grill on which the plant material is placed. The main advantages of the hydro diffusion method are that less steam is used and there is a shorter processing time. This method also increases the amount of oil extracted.
Cold pressing is the method used to extract the essential oils mainly from citrus fruits. These include orange, lime, lemon, etc. The whole fruits or rinds are placed in the press and slowly punctured to release the oils. The oils are collected in a collection area below the press. Many machines use centrifugal force to extract all of the essential oils from the plant parts.
Both distillation and cold pressing are effective ways of extracting essential oils from plants. The method used will depend on the plant being used for extraction and the best method for extracting the essential oils from that particular plant. Essential oils used in aromatherapy are extracted in one of these ways. It takes quite a lot of plant parts to produce a small amount of essential oils. This is the reason essential oils can be relatively expensive. However, the benefits we receive from using these essential oils seem to far outweigh the cost.
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