When the oil content in fresh plants is so small that the removal of oil is not commercially feasible by any other methods Enfleurage is used. In this an odorless, bland, fixed oil or fat is spread in a thin layer on glass plates. The plant material most often flowers or petals are placed in the fat. The fat absorbs the fragrance. It is then removed and the product thus made is known as pomade.
Flowers were being processed by enfleurage i.e. extraction of essential oil with fat in the Grasse region of France long before the modern method of solvent extraction (extraction using volatile solvents). Enfleurage is an old fashioned method, passed on from father to son and perfected in the course of generations. This technique is used to capture the true odor of flowers.
Certain flowers continue to produce aroma compounds ever after picking like Jasmine and Tuberose. Fat possess a high power of absorption and when kept in contact with the flowers readily absorbs the perfume emitted. During the entire process, which lasts for 8 to 12 weeks, freshly picked flowers are layered over the fat base, kept for 24hrs or more depending on the flower, and then replaced with fresh flowers. The fat is not renewed during the process. At the end the fat is saturated with the flower oil which is now known as pomade. The oil can be extracted from the pomade by washing it with alcohol. The resulting product is known as absolute de pomade.
Hot maceration is a modification of enfleurage. In this the time required for the concentration of fat with oil is reduced. Plant material is immersed in molten fat for 1 to 12hrs depending on the plant species. After each immersion the used plant material is separated and new added. After 10 to 12 immersions or till the fat is saturated, the fat is separated from the waste flower and water. This process is mainly used for highly delicate flowers which loose their fragrance rapidly like Lilly of the valley.
