As you browse the Essentique site or the boutique’s shelves for essential oils and blends, the question must have crossed your mind; what exactly is an essential oil and how is it made? For all of you aromatherapy lovers, hopefully you are interested in learning a little more about extraction methods.
It’s crucial to note that essential oils contain only the essence of whatever plant, fruit, vegetable, or spice that they are extracted from. This explains why their scent is super concentrated and requires dilution to fully benefit from their various uses in improving aspects of health and mood. In order to obtain a certain essence, extraction from the plant material required for a specific essential oil is performed. The main extraction methods are distillation, expression, absolutes, and solvent extraction.
Distillation is the most popular method of essential oil extraction. This ancient process dates back to 5000 years ago when a famous child prodigy from Persia was credited with perfecting distillation by improving the cooling process for extraction. Most commonly, essential oils are created through steam distillation, when the botanical ingredient is placed in a “still” while steam flows into the chamber, breaking up the plant’s different chemical compounds. Some of the compounds shift from vapor to liquid phase easily. Called volatile constituents, they are responsible for the scent and other beneficial properties from essential oils. The steam breaks up these compounds, allowing them to vaporize and rise into another chamber, called a condenser. This chamber condenses the vapor into a liquid form, which then drips down into a chamber with water. Since water and oils repel one another, the oil rises to the top and is ready to be collected.
Another type of essential oil extraction is called expression, otherwise known as cold pressing. Expression is used for citrus essential oils – lemon, lime, grapefruit, orange, etc. In the past, expression would be done by hand where the citrus would be soaked in warm water (so it was easier to work with) then a sponge would be pressed on the rind to absorb oils and juices which were later separated by siphoning. Today, expression is quite simple; the rinds of the fruit are punctured over and over again, and the liquid that is released is collected in a process called Écuelle à piquer. Then the juice and essential oil must be separated, most often by using centrifugal force. The main difference between expression and distillation is seen in expression’s more precise citrus scents however these oils also run the risk of containing harmless residues such as waxes (which can clog diffusers) and they tend to be more photosensitive.
Concretes, resinoids, and absolutes are a type of essential oil that cannot be distilled or expressed because the plant material used is very fragile. The volatile compounds are extracted using hydrocarbons, most often hexane. However, the three have some differences. Concretes are made from delicate botanical matter, and often contain other plant tissues than just the volatile compounds, creating a liquid that is very colorful and more stable than most essential oils. Resinoids are created by using very resinous plant matter, such as labdanum, frankincense, and galbanum. Finally, absolutes are extracted with ethanol. After the ethanol evaporates, an extremely concentrated form of essential oil is what is left and utilized. They are often the most expensive type of essential oil and capture the aroma of the original plant most closely. If you have seen the Jasmine Grandiflorum Absolute in store or online then you found one of the few absolutes we carry.
CO2 extraction is another solvent-based essential oil extraction method and also has the added benefit of sounding very cool. The solvent used here is the same gas that we exhale when we breathe. The carbon dioxide is placed under heavy pressure and low heat, turning it into a liquid. The high pressure allows the volatile compounds of the botanical material to be released. Next, the carbon dioxide depressurizes and turns back into normal CO2 gas, leaving behind the essential oil. Essentique carries a CO2 extract – the very prized Vanilla Bourbon CO2 extract.
Sound complicated? Well, yes, it is pretty complicated. But whether you are completely devoted to aromatherapy or simply dabble in essential oil usage, it’s pretty interesting and important to learn and know how essential oils are made and where yours are coming from.