Essential Oil Extraction Methods

Ever wondered how are essential oils produced? 'Essential oil' is a generic term applied to all aromatic products, such as essence oils, absolutes, resinoids, and concretes. To extract essential oils, aromatic essence molecules of the plants are targeted and extorted by various methods. Different parts of the plants are used for the process. For instance, lavender is extracted from its flowers, while orange comes from the rind of its fruit. On the other hand, frankincense is derived from the resin of its tree, cinnamon from its bark and pine is extracted from its needles. For producing a good essential oil, the plants need to be blessed with good quality soil and favorable climatic and geographic conditions. Coming to the extraction process, there is an assortment of methods used for extracting essential oils. Depending on the method and the quantity of the raw material used, the price and quality of the essential oil is determined. To get detailed information about each of theessential oil extraction methods, read through the following lines.

An age old practice, distillation is believed to have its roots well laid in the 8^th century. The most popular amongst other essential oil extraction methods, it is mostly used for leaves, flowers, seeds, roots, and stems. The technique of low pressure produces the best quality of essential oil for aromatherapy purposes. For the process, two large containers are used. The first container is filled with aromatic raw materials and steamed water, heated at low pressure, is made to pass through it.

 

The steam simmers the contents, causing the release of essential oils from the plant. This essential oil moves from the outlet into the other container. The second container, containing cold water and serpentine, changes the form of the essential oil from vapor to liquid. The water and essential oil mixture is further passed through a vessel called an alembic, wherein essential oils separate from the water. While the oils are used for the aromatherapy process, the by-product is used as floral water, examples of which are rose water, orange water and lavender water.

This method is usually used for extraction of essential oils from their fruit. It is basically a cold pressed method of extraction. Mainly essential oils extracted from citrus fruit, such as lemon, mandarin, bergamot and lime, make use of this process. Expression is a simple method and uses machines for the purpose of extraction. The machines apply a centrifugal force, squeezing the rind of the fruits, thereby producing the essential oil.

 

Enfleurage is usually practiced to extract oil from delicate flowers, such as rose, jasmine, neroli, and violet. The process involves the use of fixed oil, such as oil, animal fat or lard. For the process, a sheet of glass layered with fixed oil is mounted on a wooden rack. The raw materials and flower petals are placed on the glass, which is later exposed to sun. The heat of the sun causes saturation of the fixed oil, with essential oil of the raw materials. This fixed oil is then dissolved in alcohol. Later on, alcohol is evaporated, giving rise to pure essential oil. The oil produced in the process is labeled as 'absolute', rather than 'essential oil'. Since the process is extremely expensive one, it is rarely practiced. 

The method of maceration is almost same as that of enfluerage. The only difference between the two is that while the latter uses natural heat (i.e. heat from the sun) for the process, in maceration, fixed oil is artificially heated to facilitate the release of essential oil.

 

The process of solvent extraction is usually practiced in case of delicate flowers, such as rose, jasmine, violet, and mimosa. The method uses volatile solvents, such as petroleum ether, to extract essential oils. In this method, flower petals are kept on perforated metal trays and sprayed with the solvent. This solvent gets absorbed by the flowers and makes them release their essence. Alcohol is then added to extract the essence. Though the oil extracted from this method is also termed as 'absolute', the process is slightly less expensive than enfleurage.