We are often asked the difference between the numerous fragrant plant extracts we carry at Snowdrift Farm. At this writing, we carry essential oils, absolutes, CO2 extracts and floral waxes.
An essential oil is the aromatic and volatile extract of a plant. The essential oil may be liquid, semi-solid or solid, depending upon the product and climatic conditions. Oils are obtained through expression or steam distillation of the plant. We use these oils in soap and lotion making, as well as candles, potpourri, aromatherapy and perfuming. According to Jeanne Rose, “Some essential oils are not in the living tissue, but are formed during the destruction of the living tissue. Certain botanical species have little scent, but they produce a volatile or essential oil when macerated begins a fermentation (destructive) process. The macerate is then distilled the volatile oil comes off.” (1)
Concretes are highly concentrated solid or semi-solid perfuming materials. They are waxy to the touch. Concretes are made by alcohol or ether extraction of the essence of the plant material from an existing source, such as a pomade or enfleurage. We use concretes in perfuming and to make absolutes.
An absolute is a complex material. To obtain an absolute, you must first have the concrete, as described above. Absolutes are extracted from concretes via alcohol. Most absolutes are liquid, but certain ones are semi-solid or solid. “Absolutes can also be obtained from the water of the distillation process such as Lavender water-absolute or Rose water-absolute…The part of an absolute one can steam distill is called an absolute oil.”(2)
CO2 extraction or supercritical CO2 extraction is another method of capturing the essence of the plant material. CO2 extracts are usually semi-solid to solid, though there are a few liquid examples. CO2 is vaporized and dissipated into the plant material, leaving only the extracted material behind. Some perfumiers prefer CO2 extracts believing the method is purer (no alcohol or solvents are used) and less heat intensive. Although the cost of CO2 is reasonable, most CO2 extracts tend to be expensive. Most handcrafters use CO2 extracts in fine toiletries and perfuming.
Used in perfuming, resinoids are obtained from naturally resinous materials, such as fir, pine or balsa trees, via hydrocarbon extraction. Oleoresins: Oleoresins may be obtained naturally, as seepage or exudation, from plants. Most commonly, oleoresins are obtained through the solvent extraction of the plant material. They are used widely in food preparation and cosmetics and toiletries. These concentrated resins are usually colorful, so be prepared for a color shift in your product if you use these materials.
Check Snowdrift Farm’s essential oils, absolutes and CO2 extracts here!
(1) Jeanne Rose, THE AROMATHERAPY BOOK, p. 54, c 1992, North Atlantic Books
(2) Ibid, p. 45