Manufacturing Perfumes

Odorants from natural sources require the use of various methods to extract the aromatics from the raw materials. The results of the extraction are either essential oils, absolutes, concretes, or butters, depending on the amount of waxes in the extracted product. All these techniques will, to a certain extent, distort the odour of the aromatic compounds obtained from the raw materials.

Maceration/Solvent extraction: The most used and economically important technique for extracting aromatics in the modern perfume industry. Raw materials are submerged in a solvent that can dissolve the desired aromatic compounds. Maceration lasts anywhere from hours to months. Fragrant compounds for woody and fibrous plant materials are often obtained in this manner as are all aromatics from animal sources. The technique can also be used to extract odorants that are too volatile for distillation or easily denatured by heat. Commonly used solvents for maceration/solvent extraction include hexane, and dimethyl ether. The product of this process is called a "concrete".

Supercritical fluid extraction: A relatively new technique for extracting fragrant compounds from a raw material, which often employ Supercritical CO2. Due to the low heat of process and the relatively nonreactive solvent used in the extraction, the fragrant compounds derived often closely resemble the original odour of the raw material.
Ethanol extraction: A type of solvent extraction used to extract fragrant compounds directly from dry raw materials, as well as the impure oily compounds materials resulting from solvent extraction or enfleurage. Ethanol extraction is not used to extract fragrance from fresh plant materials since these contain large quantities of water, which will also be extracted into the ethanol.

Distillation: A common technique for obtaining aromatic compounds from plants, such as orange blossoms and roses. The raw material is heated and the fragrant compounds are re-collected through condensation of the distilled vapour.

Steam distillation: Steam from boiling water is passed through the raw material, which drives out their volatile fragrant compounds. The condensate from distillation are settled in a Florentine flask. This allows for the easy separation of the fragrant oils from the water. The water collected from the condensate, which retains some of the fragrant compounds and oils from the raw material is called hydrosol and sometimes sold. This is most commonly used for fresh plant materials such as flowers, leaves, and stems.
Dry/destructive distillation: The raw materials are directly heated in a still without a carrier solvent such as water. Fragrant compounds that are released from the raw material by the high heat often undergo anhydrous pyrolysis, which results in the formation of different fragrant compounds, and thus different fragrant notes. This method is used to obtain fragrant compounds from fossil amber and fragrant woods where an intentional "burned" or "toasted" odour is desired.

Expression: Raw material is squeezed or compressed and the oils are collected. Of all raw materials, only the fragrant oils from the peels of fruits in the citrus family are extracted in this manner since the oil is present in large enough quantities as to make this extraction method economically feasible. Enfleurage: Absorption of aroma materials into wax and then extracting the odorous oil with ethyl alcohol. Extraction by enfleurage was commonly used when distillation was not possible due to the fact that some fragrant compounds denature through high heat. This technique is not commonly used in the present day industry due to its prohibitive cost and the existence of more efficient and effective extraction methods.