The Creation of Absolute Oils

Absolute oils are like essential oils in many ways, however, they are made using a different process from essential oils, which are generally made using steam distillation and sometimes cold pressing.

Absolutes, however, are made using solvents to extract their aromatic molecules. The reason for this method is because the plant matter from which the scent is extracted, are too delicate for steam distillation. If delicate flowers such as Jasmine, Honeysuckle or Blue Lotus were steam distilled, the heat of the steam would damage the heavier aromatic molecules within the flowers and thus alter the aroma. For this reason, a the lower heat solvent extraction method is used.

If the cold pressing technique was used, so many flowers would be required to extract the oils that they would become incredibly expensive and, likely, no one would use them. Hence the solvent extraction method is used which I have explained below.

Solvent extraction is a multi-step process which starts by soaking the organic material (usually flowers) in a solvent in a cylindrical drum. The flowers and solvent are rotated in the drum to help the absorption of the solvent into the flowers. This solution is then vacuum distilled to remove the solvent which can then be recycled. The aromatic material obtained after this first process is known as a concrète or resinoid, depending if the extract is waxy or resinous.

Next, ethanol (an alcohol) is used to separate the aromatic compounds from pigments and waxes which are usually present in the extracted material if it is derived from a flower or herb. These waxes often have little aromatic value and make the oil difficult to use due to their insolubility in the oil. After being chilled, the waxes and non-odiferous materials become separated and are removed through filtration. Finally the alcohol is recovered using vacuum distillation and you have a pure absolute.

You might well see articles saying that absolutes are toxic or contain large percentages of the solvents used in their extraction. From what I have read (though not verified with testing) this is a concern left over from the initial attempts at using solvent extraction in the 1950's. At that time, many of these techniques were less well refined meaning the resulting absolutes contained discernable quantities of solvents. Nowadays, the levels of solvent left in an absolute are typically in the order of magnitude of 10 parts per million. This means that when they are diluted down to 1% (way more than any recipes I have in my products) any residues will be diluted down to parts per trillion - not, in my view a cause for concern! It's also worth noting that solvents are very expensive so manufacturers are highly incentivised to recapture every last drop of them for recycling to maximise their profit.

Having spent time smelling a lot of absolutes, I can assure you that their quality varies significantly. As I have not been behind the scenes in every factory producing absolutes, I cannot confirm the exact cause of these differences. I can confirm, however, that many absolutes are made using hexane (a known neurotoxin which should not be inhaled!) and none I sell are extracted using hexane. I am not sure if that fully explains why the absolutes I have sourced lack the toxic aroma present in many absolutes I have inhaled, or if it's simply that the solvent removal techniques used in the ones I have selected are superior. What I can confirm is that there's no more economical way of producing an oil from delicate flowers than solvent extraction and the absolutes I stock are absolutely fabulous!