Essential Oil Recipe Journal
Today's guest post will talk about how essential oils are made & discuss the 3 broad extraction processes: distillation, expression and solvent extraction.

How Essential Oils Are Made: The Three Extraction Processes

Today's guest post will talk about how essential oils are made & discuss the 3 broad extraction processes: distillation, expression and solvent extraction.Have you ever wondered how essential oils are made? I am very happy to be able to share a guest post written by Trysh at Pure Path Essential Oils which will break down the different processes used to create essential oils. This post is super informative and definitely taught me a few things, I think you will enjoy it!

Without further ado, let’s turn it over to Trysh!

How Essential Oils Are Made

The popularity of essential oils has never been higher. The ways to use essential oils are also becoming increasingly creative.

Aromatherapy, cosmetic supplies, and even cooking recipes are using essential oils as their base because the absolute essence of a plant is in its oil.

But how do you separate the oil from the plant?? There are actually multiple ways that this can be done. The three broad extraction methods are Distillation, Expression and Solvent Extraction:

 

Steam Distillation

Most commercial essential oils on the market today have been extracted through the process of distillation–specifically, steam distillation.

In short, steam pulls the oil from the plant matter and the vapor carrying the oil is captured. Once cooled, a high-quality essential oil is left behind. This is an extremely efficient way to acquire the essential oil of an ingredient.

The byproduct of this process is highly aromatic water, also known as a hydrosol. The oil doesn’t mix with the water and sits atop the solution and is skimmed off. This leftover water is, in its own right, known for its aromatherapy benefits but it’s nowhere as potent or versatile the oil.

Below are the steps to the most common form of distillation.

  1. The plant matter is placed in a large stainless steel container, called a still.
  2. Steam is pumped into the tank, blasting through the plant material and extracting the oil. The plant’s aromatic elements turn into vapor.
  3. The plant’s vapor molecules float into a condenser which is inside what is called a cooling tank. Cold water is injected into the cooling tank which causes the vapor in the condenser to cool and therefore turn back into a liquid.
  4. The newly formed, cooled liquid is deposited into a smaller container underneath called the separator. Oil and water don’t mix, so as the solution settles, the oil rises and sits on top of the water.
  5. The oil is siphoned from the top and placed into a larger tank containing the specified oil for filling retail bottles.

For a visual representation of the process, click here or here.


 

Expression

The process of expression is ideal for the extraction of oil from citrus or other ingredients that contain heavy amounts of nutrients on their surface. Lemon essential oil’s benefits, for example, all come from nutrients and properties within the skin of the fruit.

Expression is sometimes called cold-pressing because the process typically involves the slow rotation of a heavy, spiked roller along the skin of a dry citrus peel without applying any outside heat. The roller squeezes and agitates the skin releasing the natural oils into a container below.

This process used almost exclusively for the collection of citrus essential oils.

Prior to the invention of the distillation process, expression was the only method of extracting essential oils. This process was also done solely with human power. Today’s modern methods use mostly machines to express the oils. Large centrifuges spin the material so quickly, every single drop of oil is released from the medium.

Many people prefer expression as a process for their extracted oils because it hasn’t been touched by heat or any chemicals.

 

Solvent Extraction

The usage of chemical solvents was highly prevalent in the early days of extracting essential oils. As time has passed, we’ve discovered a variety of ways to gather the essence that are safer and just as (if not, more) effective.

Some oils cannot be extracted through distillation or expression and need to be coaxed out a different way. Jasmine is an example of a plant that does not respond well to these processes but thrives when extracted by solvents. Hexane is the typical chemical used in solvent extraction these days. Others include methanol and ethanol.

It’s an expensive process but they prove to be great at getting essential oils (or technically – absolutes) from hard to extract plant material or those that are too delicate for steam distillation or expression.

The finished product of chemical solvent extraction is called an absolute instead of a pure essential oil. It also contains some residue of the chemical used and although very small, many aromatherapists still stay away from them.

Two subtypes of solvent extraction are enfleurage and hypercritical carbon dioxide:

Enfleurage

Enfleurage is a process still used in France but is lesser known around the globe. The process is traditional of the way it was done in the past with limited technology.

French farmers carry plenty of extra pig fat or lard for cooking and other uses. They realized that if you put the plant materials into the fat, the fat ends up absorbing the fragrance.  

The process of enfleurage involves placing the loose material into an animal fat–usually lard or tallow. The plant material sits while the fat leaches out the oils. After it’s been sitting for a few days, it becomes exhausted–or gives up all of its oils. The old plant material is replaced and the process continues.

To complete the process, the fat containing the essential oil is dissolved by alcohol, leaving only the prize behind after the alcohol has evaporated.

Most enfleurage practitioners today employ the use of vegetable oil instead of animal fat.

 

Hypercritical Carbon Dioxide

Carbon dioxide extraction is relatively new to the area of essential oils. The process is very expensive due to the equipment involved so only a few manufacturers are currently making essential oil this way. They say that it’s worth the extra expense as it gives them an oil that smells exactly like the source and more potent than other extraction methods.

The process involves combining CO2 and the plant material. Carbon dioxide is pressurized into a tank in its gaseous form. This increased pressure converts the pure gas into a liquid-gas hybrid which becomes the solvent for the plant material, extracting the oils.

Unlike chemical solvent extraction, however, this method leaves behind no chemical residue.

 

Choosing Which Process to Use

The choice of which process to use for extracting essential oils depends on the ingredient. Citrus is practically made for expression and is the preferred option for any essential oil manufacturers in that market while steam distillation can be used for most other oils.  

These two are the industry favorite methods of extraction because they’re quick, easy, economical, and produce high-quality essential oils.

 

Guest Bio

Trysh Sutton is a wife, mother, former-attorney, interior decorator, strategic leader and teacher. She has an eye for business, innovation and perfection – and a desire to help her family, her friends and herself live a healthy and happy life. Read her blog about living healthy and happy at Pure Path Essential Oils. Follow her on social media: Facebook | Twitter | Pinterest | Google+ | Instagram | Youtube

 

 

 

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