Aromatherapy
Lesson 1: The Journey Begins
Extraction: How Essential Oils Are Obtained
Essential oils are the ‘signature’ of the plant, its fragrant principle. I’ll often mention, throughout the course, the need to dilute the essential oils we use. It is interesting to note that plants never use essential oils in their pure form. They store their essential oils in pouches and retrieve them in a diluted form whenever they’re needed. Isn’t nature smart?
Essential oils are usually located on the outer part of the plant (the skin of citrus fruits or the surface of the leaves) thus explaining the great affinity essential oils have for our own skin.
The different methods of extraction are based on three main characteristics:
- Essential oils are volatile (from the Latin “volare”, to fly), which means they evaporate completely when exposed to air. This is the reason why we can smell them and benefit from the inhalation of small amounts. This specific quality allows us to extract them through distillation.
- Essential oils are also lipophyle, which means they are easily absorbed by vegetable oils, fats and waxes. Thanks to this quality, we can extract oils from flowers through the extraction process called enfleurage.
- Essential oils are also hydrophobic, which means they do not mix with water. This is important for the final stage of steam distillation.
OIL INFUSION
Oil infusion, also called extraction by fats, is probably the oldest method of extraction. Plants are soaked in vegetable oil in a glass jar and exposed to the sun for approximately two weeks. At the end of the two-week period, the plants are strained out and more herbs are added to the fragrant oil. This is how the amazingly healing St. John’s Wort’s oil is made in France.
ENFLEURAGE
Enfleurage is obtained by placing a layer of fresh flowers on a thin layer of fat (usually lard), or on an oil-soaked cloth. Every day, the flowers are replaced with fresh ones until the right degree of concentration is obtained. Since this method does not allow the separation of essential oils, the final product will be used in creams, massage oils and bath oils.
STEAM DISTILLATION
Steam distillation is the most common way of extracting essential oils from the plant. The steam is forced into a vat of plant material where the little pouches are broken releasing the essential oils. After a cooling phase, the oils are finally collected. This is the most popular method of natural extraction.
EXPRESSION
When essential oils are squeezed or cold-pressed from the fruit, this method is called expression. This is the method utilized to extract essential oils from citrus fruits, since their oils are present in the skin of the fruit and the steam distillation process would alter and damage their composition.
SOLVENT EXTRACTION
Given the increasing market demand for essential oils, solvent extraction is now often utilized. It is important to realize that this method DOES NOT PRODUCE PURE ESSENTIAL OILS. The outcome is a highly scented concentrate mainly used in the perfume and food industry. The plants are immersed in a solvent (acetone or a petroleum byproduct) and the separation is obtained chemically. This method is used widely for neroli, rose, tuberoses, jasmine, honeysuckle, and others. These so called ‘concretes’ and ‘absolutes’ should NOT be used for aromatherapy.
CONCLUSION
Distillation and expression are the only methods of extraction that produce true essential oils. All other methods produce aromatic products primarily utilized in the perfume industry, herbal medicine and skin care.
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