Extraction refers to how the essential oil is removed from the plant material and made available for use. There are several methods of extraction. Each has benefits and depends on the type of plant material and the types of compounds you want in your final oil. Distillers may use one or more method of extraction for different plants.
Reserved for citrus extraction. The citrus fruits are rotated against rollers and bruised. The essential oils is released into a collection vessel also containing water. The water is siphoned off, leaving the oils behind since they float in the top. This method is good for citrus, since it’s not subjected to heat. The heat may destroy some of the compounds in citrus oils.
The vast majority of essential oils are created this way! For this method, steam from a boiler in piped into a vessel containing the plant matter. The volatile compounds (essential oil) are released and move through a condensing tube into a collection vessel. This vessel contains water, which is the hydrosol. The essential oil floats on the surface of this liquid. Later, the water/hydrosol/floral water is decanted off leaving the essential oil for bottling.
The benefit here is the speed in which this can be completed. Again, some compounds can be subjected to degradation under high heat conditions. If the process can be quick, the degradation can be controlled.
Reserved for oils in which compounds would be damaged by traditional steam distillation.
Flowers too delicate to be processed with heat are soaked in a solvent, usually hexane that extracts the volatile elements. The solvent is then evaporated leaving only the most fragrant constituents behind. This process produces what is called an “absolute”. Here is a more in depth step-by-step process:
- Plant material is macerated in a solvent, usually hexane
- After several days the solvent is removed, leaving the viscous, fragrant concrete
- The concrete is dissolved with high-proof alcohol
- The mixture is chilled, and separates into plant waxes and fragrant tincture
- The fragrant tincture is vacuum distilled to evaporate off the alcohol, leaving an absolute
Hydrosols or Floral Waters
The water that is siphoned off prior to bottling essential oils. As you can see in the diagram, he essential oil is floating on the surface and there is water below. THAT water is the hydrosol. These are perfect for everyday use, having many of the benefits of essential oils, but in a much gentler form. Good for cuts, scrapes and for use with children.
You can tell right on the website what type of extraction was used for your essential oil! If this information isn’t found on the label, most websites have it available to you! It’s just another important piece to the puzzle! If you have any concerns or questions please fell free to contact one of our on-staff aromatherapists at [email protected]! Also, join our Facebook group Safe Essential Oil Recipes.