Essential oils are used in perfumes, in aromatherapy, in creams and lotions and in many more products where pleasant aromas are needed. A number of methods are used to extract the essential oils from flowers and other plant material. Only a very small amount of essential oil is in each flower so a substantial amount of plant material is needed to make a small quantity of oil. Over one hundred pounds is usually necessary to produce an ounce of essential oil. A number of plants are also much too fragile to use any of the easier methods and more expensive and labour intensive ways have to be used. Essential oils are often very expensive but they are concentrated. Most recipes merely require a very small amount so a small bottle could last for a many months or years.

Steam Distillation

This technique is in use for the majority of essential oil manufacture. Steam that is under pressure is passed through flowers or other plant material that are on screens within a still. The oils are absorbed by the steam which is then passed into a different chamber where it is allowed to cool. On condensing the oil floats on the top of the water where it is easily removed. The remaining water is called floral water and is also used since it contains tiny quantities of the oil. It is used for toners and facial mists. Floral water may be used by those who are sensitive to essential oils since it is less intense.

Solvent Extraction

For plant material or flowers that are too fragile to use steam extraction, solvent extraction is often used. A solvent is passed over the flowers on mesh trays. The esential oils, together with some other materials that are soluble, dissolve in the solvent which is then filtered and the resulting solution distilled to take away the solvent. Concrete, the material produced, is a waxy solid containing the waxes, pigments and the oils from the plant material. Some more processes are then used to extract the oils and waxes from this concrete. The concrete itself can also be used as a perfume and the waxes can be used in creams, lotions and for candle making.

Enfleurage

For plants and flowers that have only very low percentages of essential oils, for example jasmine, a different technique needs to be used. Vegetable oil is used to soak the flowers and left for a few days and then replaced by fresh flowers. Fresh flowers are repeatedly placed in the vegetable oil until the oil becomes thoroughly saturated with the oils from the plant material. Alcohol is then used to extract the essential oil from the vegetable oil. On evaporation of the alcohol the pure essential oil is collected. This procedure takes a long time and needs a large quantity of flowers resulting in very expensive essential oil.

Cold Pressing

A few oils, for example citrus oil, where the oil is extracted from the fruit rather than the flowers, use a procedure called cold pressing. This entails rolling the fruit between projections with spikes which penetrate the skin and then squeeze the fruit to extract the juice containing oils. The resulting juice is then centrifuged to separate the essential oil.

Carbon Dioxide Extraction

In this method carbon dioxide is used to remove the essential oil. The gas is pumped into a chamber containing the plant material. When the pressure is increased the gas liquifies and absorbs the oils. The carbon dioxide is then let into a further chamber where the pressure is released. The gas then vaporises leaving the essential oils behind.

As no residues are left behind the oil is extremely pure and has a lovely, fresh perfume. Because a lower temperature is used than for steam distillation, essential oil can be obtained from fragile flowers that are destroyed by steam distillation.

For more information and lots more craft and hobby ideas please visit us at Easy Craft Ideas or Essential Oil Recipes

No related posts.

Related posts brought to you by Yet Another Related Posts Plugin.