How Essential Oils Are Made

Solvent Extraction
There are many variations of solvent extraction, but the basic premise of each one is using a certain chemical solvent on a (usually) flower or plant. This is a method that is usually used when the plant material cannot stand up to the heat of steam distillation and when cold pressing is not an option.

The process is fairly basic. The first step is to decide what chemical solvent to use and then to mix it with the plant material for a while. The chemical solvent draws the essential oils out into itself, and after a while, the plant material is removed from the solvent, leaving behind a combination of the solvent/wax and oil called concrete. Then, alcohol is applied to the concrete to dissolve the wax from the solvent. Once the alcohol evaporates, the oil is left there for collection.

While this method can often produce larger amounts of oil, it is often criticized because remainders of the chemical solvents are never completely removed. This means that every solvent-extracted oil has at least a tiny bit of solvent left attached to it.

Usually this residue is too small to make a difference, but a few unwise vendors may still use solvents like benzene, which can leave behind a residue of up to a whopping 20% of the extraction. On the brighter side, benzene is a carcinogenic (cancer-forming), so the large majority of oil producers will not use it as a solvent. Instead, other solvents (they all have to be hydrocarbons), like hexane, can be used to produce cleaner oil without any carcinogenic side effects.

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