Essential Oils: The Basics, Part 3: How are essential oils extracted?

Thousands of years ago humans understood the importance of plants in their life whether it was for food, shelter or medicine and through trial and error our ancestors learned how to use and maximize the benefits of these plants.  In fact, without photosynthesis- the exchange of carbon dioxide and oxygen with every breath we take- neither humans nor plants would exist.

Humans started to tinker with distillation around 3000BC and as the world evolved, distillation became important in four areas: laboratories, industry, herbs for perfumery and medicine, and food processing.

Fast forward to 2019 and the evolution of processing herbs for perfumery and medicine still consists largely of distillation but it also includes a few modern inventions.

Today I will share with you three methods of essential oil extraction that are most commonly used:

STEAM DISTILLATION:

Steam distillation is by far the most popular method used to extract and isolate essential oils from plants for use in natural products.  This happens when steam vaporizes the plant materials volatile compounds, which eventually go through a condensation and collection process.

1) A large container called a STILL contains the plant material and has steam added to it.

2) Through an inlet, steam is injected through the plant material containing the desired oils, releasing the plant's aromatic molecules and turning them into vapor. 

3) The vaporized plant compounds travel to the condensation flask, also known as the condenser.  Here, two separate pipes make it possible for hot water to exit and for cold water to enter the condenser.  This makes the vapor cool back to liquid form.

4) The aromatic liquid collects in the separator and because oil and water don't mix, the essential oil floats to the top of the ware.  From here it is siphoned off.
Steam distillation is used in WCB oils such as lavender, sandalwood, rosemary and cedarwood.

 

 

SOLVENT EXTRACTION:

This method employs food grade solvents like hexane and ethanol to isolate essential oils from plant material.  This method is best suited for plant materials that yield low amounts of essential oils, especially those cannot withstand the pressure and distress of steam distillation.  This method produces a finer fragrance than any type of distillation method.

Once the plant material has been treated with a solvent, it produces a waxy aromatic compound called a "concrete". When this concrete substance is mixed with alcohol, the oil particles are released.  These aforementioned chemicals used in this process then remain in the oil and this is used in perfumery and aromatherapy.

The rose essential oil, used in the NAPA blend from WCB, uses this method of extraction.

COLD PRESS EXTRACTION

This method is also called expression and is used for citus peels in particular.

1) The whole fruit is placed in a device that mechanically pierces it to rupture the essential oil sacs, which are located on the underside of the rind.  The essential oil then runs down to the collection are.

2) The whole fruit is pressed to squeeze out the juice and the oil.

3) The oil and juice that are produced still contain solids from the fruits and must be centrifuged to filter the solids from the liquids.

4) The oil separates from the juice layer and is siphoned off into another receptacle.

The bergamot, mandarin orange and sweet orange used in the WCB blends are made using this technique.

I hope you enjoyed this brief education on how essential oils are obtained using the most common methods of extraction. Stay tuned for the next blog where I will tell you about more EXOTIC extraction methods and how the end product is unique from traditional methods.

Wishing you beauty, balance and wellness.... Nicole

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