Straight from Wikipedia I thought this was a good explanation of an absolute:
Used in perfumery and aromatherapy, absolutes are similar to essential oils. They are concentrated, highly-aromatic, oily mixtures extracted from plants. Whereas essential oils can typically be produced through steam distillation, absolutes require the use of solvent extraction techniques or more traditionally, through enfleurage.
So basically absolutes are essential oils derived from solvent extraction or enfleurage.
Enfleurage is a term to describe the extraction process. It can be cold or hot and unfortunately animal fats are used. Right off the bat that turns me off. I’m a vegetarian and have been for nearly 30 years. I don’t wear leather and try to be mindful of everything I buy or consume in my life. I don’t buy absolutes for this reason. This method was created hundreds of years ago specifically for perfumery. I really can’t think of anything worse than mixing botanical substances in hot tallow to extract a scent. Blah. And if you didn’t know - hoofs and other materials from the bodies of horses, cows and pigs are boiled up to make things like tallow and gelatine.
I’m not even sure if this method is used in commercial production at all.
In both instances, once the fat is saturated with fragrance, it is then called the “enfleurage pomade”. The enfleurage pomade was either sold as it was, or it could be further washed or soaked in ethyl alcohol to draw the fragrant molecules into the alcohol. The alcohol is then separated from the fat and allowed to evaporate, leaving behind the absolute of the botanical matter. The spent fat is usually used to make soaps since it is still relatively fragrant.
Then there’s solvent extraction which usually uses some type of chemical to extract the scent. Often hexane is used which some people claim is safe, but I’m not quite sure about that. It’s usually alcohol that’s used and I suppose it’s relatively harmless. When this method is used a “concrete” is formed, which is then soaked in alcohol. When the alcohol evaporates, the absolute remains.
Gasoline has a high amount of hexane but I’m not sure about the origin of the hexane that used in absolute production. I’m unsure if it would come from petrol, or if it would be synthesized in a lab and sold by chemical companies. At any rate, I’d prefer to buy a steam distilled oil, or an oil produced by CO2 extraction which is also called Super Critical extraction. That sounds a bit wrong but the CO2 method seems to be an environmentally friendly way to extract aromatic compounds. I’ll do a separate article on that.
Oils that you may find as an absolute -
Lotus – pink and white
And there are probably lots more too. It’s totally up to you as to what oils you buy but I prefer to choose oils that have a more simple extraction method.