Enfleurage is a process that uses odorless fats that are solid at room temperature to capture the fragrant compounds exuded by plants. The process can be "cold" enfleurage or "hot" enfleurage.

The process of enfleurage

In cold enfleurage, a large framed plate of glass, called a chassis, is smeared with a layer of the fat and allowed to set. Botanical matter, usually petals, is then placed on the fat and its scent is allowed to diffuse into the fat over the course of 1-3 days. The process is then repeated by replacing the spent botanicals with fresh ones until the fat has reached a desired degree of fragrance saturation. In hot enfleurage, solid fats are heated and botanical matter is stirred into the fat. Spent botanicals are repeatedly strained from the fat and replaced with fresh material until the fat is saturated with fragrance.

In both instances, the fragrance-saturated fat is now called the "enfleurage pommade ". The enfleurage pommade is washed or soaked in ethyl alcohol to draw the fragrant molecules into the alcohol. The alcohol is then separated from the fat and allowed to evaporate, leaving behind the essential oil of the botanical matter. The spent fat is usually used to make soaps since it is still relatively fragrant.

Other fragrance extraction methods

This method of fragrance extraction is by far one of the oldest. It is also highly inefficient and costly but was the sole method of extracting the essential oils of delicate floral botanical such as jasmine and tuberose, which would be destroyed or denatured by the high temperatures required by methods of fragrance extraction such as steam distillation. The method is now superseded by more efficient techniques such as solvent extraction or supercritical fluid extraction using liquid carbon dioxide (CO₂) or similar compressed gases.