Happy 4th of July everybody!
I was recently asked "What is the difference between an essential oil, an absolute, and a fragrance oil?" Since I already blogged about the difference between essential oils and fragrance oils, I'll focus on absolutes.
An essential oil is a liquid that is generally distilled (most frequently by steam) from the leaves, stems, flowers, bark, roots, or other elements of a plant. These are oils that are naturally occuring in the plant, often referred to as the plant's essence (thus named "essential oils").
Absolute oils are natural oils extracted from flowers, leaves or bark. An absolute oil is not really an essential oil, it is an essence. They have very high concentrations of fragrance and a little goes a long way. Absolute oils are also generally more expensive to buy than essential oils, because the process of extraction is more difficult, time consuming, and expensive.
Here are the "short & sweet" steps of extracting oils for absolutes:
- The botanicals are placed in drum together with a solvent mixture, usually alcohol or some other hydrocarbon such as hexane . The solvent is then allowed to be absorbed into the extract. Vacuum distillation is then applied to remove the solvent, leaving behind a material called a concrete or a resin. Another method is through enfleurage: The botanicals are placed in fats, allowing the fragrance to be absorbed into the fat over the space of a few days. This process is repeated until the fat is saturated with the desired density of fragrance.
- The concrete (or resin) is washed with alcohol to extract the aromatic compounds, after which it is distilled to leave behind the pure essence, the absolute oil. There is now a new method of absolute oil extraction but it is very expensive - through the use of carbon dioxide. This carbon dioxide acts as a solvent which almost instantaneosly extracts the oil, and because of the low temperature, there is no heat damage to the oil. Due to the expense of this process, however, it is not yet widely used, but is the most natural method of extraction for absolute oils.
I hope this helps everyone understand the difference between essential oils and absolute oils. Keep in mind that absolute oils CAN be extracted without the use of chemicals, and you can now find those natural options, especially on the internet.
Do you have experience working with absolutes? What are your feelings about them? Let us know.