Distillation of essential oils
Distillation is the most common method used for the extraction of a plants’ essential oil.
Distillation is the method used for over thousands of years, mainly for the production of alcoholic beverages. The procedure used for the distillation of the essential oils is steam distillation. This procedure is based on the findings of an 11th century Persian physician called «Avicenna» who introduced and documented many medical procedures still used today, including aromatherapy. Over the centuries, the distillation process and equipment have improved and modernized. Nevertheless, the basic concept remains the same.
There are three variations of the distillation process:
1) Hydro distillation
2) Distillation with water and steam
3) Steam distillation
All these operate in the same basic manner. The process involves the use of water vapor by heating a mixture of the raw material.
Heat is channeled through an alembic and the heat of the steam breaks the fibers of the plant. This heat is sufficient to release the essential oils, which are entrained by the water vapor out of the alembic (retort). The mixture of steam and oil is cooled and becomes concentrated, usually producing a layer of essential oil and a layer of water. Since the density of the essential oil and water are different (the essential oil is lighter than water), the essential oil rises to the top. The distillation of various aromatic plants and flowers can lead to the production of two products. One is the essential oil and the other rosewater, water in which a small amount of essential oil has been dissolved.
Essential oils are often used in perfumery and aromatherapy while floral water has many applications in aromatherapy, food processing and skin care.
Hydro distillation: is the simplest of all the processes and is achieved when the plant is placed in water, which is then brought to a boil. While this method is necessary for some plants, especially for the stem of a plant, the distillation of oils from plants such as lavender works better with the below mentioned steam methods.
Distillation with water and steam: is a process where the plant is placed into the alembic retort over the boiling water through a screen. The advantage of this is that the steam penetrates