Is an age-old technique for extracting aromas out of raw materials into fragrant and usable substances for the perfume industry. It can be performed on a variety of different materials, from wood, to roots, to flowers, to seeds, to leaves, and even bark. The result is usually the creation of an essential oil, which is made up of various active ingredients, as well as aromatic compounds. These essential oils have a wide range of uses, featuring themselves extensively in the field of perfumery, as well as in aromatherapy. The quality and preciseness of the process determines the quality of the end product, and the degree of refinement of the essential oils determines the grade — some being finer than others.
Another common substance derived from distillation is the product known as hydrosol. Water is boiled and steam is sent through the source material, for a period of an hour to an hour and a half. After various other complex and specific steps, the result is a pure essential oil, and an aromatic water solution which becomes hydrosol. The inconsistencies with the quality of hydrosol — often being hard to replicate good batches — make it relatively rare in perfumery, but systems are being perfected to mitigate these issues.
A specific process that uses the foundational processes aligned with distillation is fractional distillation, who’s invention was spurred by a necessity to extract the essential oil of the ylang-ylang tree. This process takes longer, and involves the use of a fractioning column whose purpose is to yield multiple grades of the same fragrant compound. This process is especially valued by a perfumer who desires greater control over the ends result.
Rectification is a variation of the distillation method, and is often called dry distillation. The method involves the use of heat, without any carriers like water or alcohol, and the result yields a smoky, burnt, tar-like aroma. It is often implemented in order to recreate leather aromas, or the smells associated with fossilized amber.