Steam Distillation

When producing Essential Oils, the most common method used is what is known as "Steam Distillation". This appears to be the best method so far for extracting most Essential Oils, although the CO2 method is also becoming quite popular as we will see later.

Most Aromatherapists feel that an essential oil is not a "true" essential oil unless it is steamed distilled and therefore oils extracted from the other methods should be called exactly what they are; cold pressed oils, concretes, absolutes, etc. and should not be confused with "true" essential oils.

In the steam distillation process the material is carefully gathered and placed into either a copper or stainless steel vat, known as the distillation chamber. Steam is then applied through heat (preferably low heat) and pressure builds within the distillation chamber causing the glands of the plant to rupture and to give up its essence which is then released in the steam vapor.

This steamy vapor is passed through a refrigerated coil, which is usually submerged into cold water. This causes the vapor to cool and condense. Here the water and essential oil will separate due to the cooling effect. The essential oils will usually stay on top of the water due to the difference in gravity. The water and essential oil are sent to a collection chamber where the oil can be easily skimmed off of the top of the distillated water.

The distillated water still contains many of the water soluble content of the plant and is very mild. These can be used in skin care, and are safe for children and the elderly. This is known as a "hydrosol" and is a byproduct of the distillation process.

When subjecting a plant to heat or steam as in the distillation process, the chemicals within the plant after distillation are different than the original plant. This has caused some problems in many books on the subject of aromatherapy because the writers are giving the attributes of the particular herb that was used for the Essential oil, but the Essential oil and the herb are different once the distillation process is complete.

It is imperative to remember that the essential oil of a plant is not the same as the plant itself. When subjecting the plant to heat or steam as in the distillation process, the chemical structure within the essential oil after distillation are different than those found in the original plant material. For instance, Chamomile produces the chemical azulene, which is not found in the plant itself but is produced only during the distillation procedure.

Fractionated Oils: A fractionated oil is an essential oil that has been redistilled, usually at a higher temperature to remove certain components. Ylang Ylang is a common oil that has 5 different fractions. Another common oil is Bergamot that is fractionated to remove the furocoumarins, known as Bergamot FCF.

List Of Parts Used In Distillation

Fruit Peel: Citrus oils. These include Grapefruit, Bergamot, Mandarin, Orange, Lemon, Lime and Tangerine.
Bark: Oils such as Cinnamon and Birch are used by distilling the bark.
Leaves & Stems: Basil, Cajeput, Cinnamon, Clary Sage, Cypress, Eucalyptus, Geranium, Hyssop, Marjoram, Myrtle, Verbena, Melissa, Niaouli, Oregano, Petitgrain, Patchouli, Pine, Peppermint, Rosemary, Sage, Savory, Spearmint, Spruce, Tea tree, Thyme.
Grasses: Citronella, Lemongrass, Palmarosa.
Flowers: Jasmine, Rose, Neroli, Ylang Ylang, Lavender.
Roots: Vetivert, Ginger, Angelica.
Resins: Frankincense, Benzoin, Myrrh, Galbanum, Elemi.
Wood: Sandalwood, Rosewood, Cedarwood, Camphor.
Seeds : Coriander, Cumin, Fennel, Carrot, Aniseed, Nutmeg.

Using different parts of the plant will result in a totally different essential oil with a completely different chemical structure.

For instance, Cinnamon can be distilled using the bark or the leaves.

" Cinnamon Bark produces a large amount of cinnamaldehyde which is a strong sensitizer and should never be used in aromatherapy.

" Cinnamon Leaf, on the other hand produces mostly Eugenol, but again should not be used on the skin.

Another example ..... (Read about our Aromatherapy Course for more information)