How are essential oils manufactured? Extraction methods explained

Heather Campbell
 min read

Explaining how essential oils are manufactured could be a little more complicated than originally suspected.

How are essential oils manufactured? Extraction methods explainedNowadays, essential oils are more and more present in our daily life. These plant substances are used in fields as varied as cosmetics, cooking or aromatherapy.

Essential oils are obtained through different extraction and manufacturing methods, depending on the plant or fruit. Some undergo a distillation or solvent extraction, while the more expensive methods involve CO2. Chemotype oils help standardization, while others are totally natural.

But what do we really know about essential oils?

Scroll down to learn more about what they are exactly, where they come from, and how to use them.

How are essential oils manufactured? Introduction to this odorous substance

By definition, essential oils are the “aromatic essences of the plant”. However, they should not be confused with those used in the field of perfumery where aromatic essences are called “perfume”.

Aromatic essences also exist in the field of cooking, but just like in the perfume industry, these aromas are different from essential oils.

So essences used in aromatherapy are called “essential oils” as opposed to “aromas”.

The essential oil is therefore an odorous substance produced by certain plants.

Being somewhat volatile, this substance can be extracted as a liquid and although called oils, these substances do not contain any fat.

A complex chemical composition

Essential oils can contain hundreds of molecules, each with very specific properties.

Indeed, they can be antiseptic, bactericidal, immunostimulant, etc. These molecules are grouped into several categories called “chemotypes” and made according to their properties.

Each essential oil can contain several chemotypes. All these molecules work in synergy and allow for the versatility of essential oils.

The beneficial actions of an essential oil are numerous, and the knowledge of the chemotypes and their concentration determine the benefits of this oil.

Chemotype or artisanal essential oil?

Chemotype essential oils come from laboratories that determine the exact biochemical structure of their products.

These oils are usually combined to obtain a specific effect for specific medical treatments.

This type of essential oil is favored by scientists because they want to standardize their manufacturing processes.

On the other hand, the artisanal oils come from manual productions and do not use any sophisticated equipment. Native or wild plants are used because they have the advantage of being untreated and entirely natural.

The artisanal school say there is a slight difference between these two types of oils which does, thankfully, affect their therapeutic virtues.

Manufacturing processes of essential oils

There are several processes to extract the aromatic essence of plants and make an essential oil.

Distillation is the most widely used of all these processes because it is the most reliable and economical.

Extraction by distillation

This method of extraction is the most widely used today. Steam is passed at low pressure through a tank containing aromatic plants.

The water vapor is loaded with the aromas contained in the plant, then sent into a coil refrigerated with cold water so that the vapor condenses and becomes liquid.

At the exit, the essential oil and the floral oil are then separated.


Another technique of extraction of an essential oil is its expression. This method, used only for citrus fruits, consists in extracting the pockets of essences located in the skin of the fruits.

The citrus fruits are then pressed so that the zests release their essences. Note that the product obtained is not called essential oil for this method, but “essence”.

This nuance in the name is explained by the fact that no biochemical modification occurred during the extraction process.

Solvent extraction

This method is used for plants, usually petals, that cannot withstand heat.

The petals are immersed in a bath of animal fat which is heated several times. The fat then absorbs the essential oil contained in the plant.

The fat is then removed to leave behind the essential oil. To do this, we use an alcoholic solvent that absorbs the essential oil without the fat.

The alcohol evaporates afterward and only the essential oil remains.

CO2 extraction

This modern extraction process allows us to obtain very high-quality essential oils.

A stream of CO2 flows through the plant masses, increasing the pressure and causing the aroma bags to burst “naturally”.

The essential oils obtained in this way have a biochemical constitution much closer to the plant’s original essence.

Unfortunately, this method is not widely used due to the high costs involved.

Precautions and recommendations related to essential oils

Aromatherapy is a very powerful medicine. The molecules in essential oils can have effects contrary to the desired effects if used in the wrong conditions.

By following a few simple rules, you can avoid any risk and take full advantage of the power of essential oils:

  • In general, essential oils are not recommended during the first 3 months of pregnancy, for nursing mothers and young children.
  • After the 3 months of pregnancy, some essential oils can be considered, but only under advice of an aromatherapist.
  • Special precautions should be taken if you are asthmatic, epileptic, have thyroid problems, cancer or stomach ulcers.
  • If you are under medication, some essential oils may be contraindicated.
  • Go for external application oils (massage) diluted in a vegetable oil and ask the advice of a specialist before taking an oral treatment or over a long period.
  • Never apply a pure essential oil on mucous membranes or near the eyes.
  • Respect the recommended doses: one drop is one drop and not two!
  • Some essential oils are photosensitizing, so avoid applying them before sun exposure.
  • For optimal storage, keep them in their original lightly tinted bottle to protect them from UV rays.
  • After use, close them as soon as possible because essential oils are extremely susceptible.
  • Some molecules contained in essential oils can be irritating. Always do a patch test on the inside of your elbow by mixing 1 to 2 drops of essential oil with a little vegetable oil, 48 hours before embarking on your treatment.

How are essential oils manufactured? Conclusion

With various methods of extraction, all dependent on the plant of fruit used, we find that essential oils are part of our daily lives.

They are now recognized for their multiple virtues on the well-being of the body and mind.

Although they are natural, you should always seek professional advice before use.

Many people are opting towards more natural remedies without chemicals, and essential oils are just the thing to encourage that.

Tip: Did you know that essential oils can also be helpful in the fight against cellulite? More information in our other posts:

About Heather Campbell

As a nutritionist, my field of specialization is science-based nutritional advice but more importantly, it is my goal to share capturing and inspiring stories, examples and solutions which can help plus-size individuals overcome their specific difficulties. Read More