How is Essential Oil Distilled?

Essential oils have a variety of beneficial uses, like helping you sleep better, relieving stress and even freshening up your home as you clean. Did you know that there are multiple ways to create essential oil from plants? 

But there is one method more commonly used, especially to extract pure essential oils from plants, and that is steam distillation.

How Steam Distillation Works

Here’s how you make essential oils using steam distillation.

First, the freshly picked plants are placed inside a chamber. Next, a steady stream of steam is pushed into the chamber. This constant flow of steam causes small sacs (oil membranes) holding the essential oils to rupture. Once that happens, the oil is transported by the steam out of the chamber and into a chilled condenser. It’s inside the condenser that the steam is promptly cooled and condensed into water again. Because oil and water don’t mix, the two components separate, and the essential oil can then be collected.

Some believe vertical steam distillation produces the best quality of distilled essential oils.

Factors that can Affect an Oil’s Quality

Besides the quality of plant material used, four factors can affect the final quality of essentials oils distilled:

1. Distillation Equipment. The material and size of the cooking chamber, condenser and separator all factor into the quality of oil. You want a non-reactive metal to use for the cooking chamber, and stainless steel is the best metal to use.

2. Time. Think of essential oils like cooking your favorite veggies. You get the best flavor and quality when you cook them longer and with patience over the stove than nuking them in the microwave. The same is true with distilling essential oils. The majority of oils turn out better when they undergo a slower cooking process.

3. Temperature. Consider vegetables again. If the temperature is too high, you’ll overcook them. And if the temperature in the cooking chamber is too high, some of the essential oils components will likely be changed or even destroyed.

4. Pressure. Pressure in the chamber is the same as the temperature. The higher the pressure, the more likely your resulting oil will have a harsh aroma and its therapeutic benefits will lessen. Low pressure and low temperature make the best quality essential oils.