Ever wonder how your favorite real-world scents are perfectly captured in a fragrance? Today in Scent School, we're going to dive into the various extraction methods that perfumers use to capture the essence of natural scents within a bottle of your favorite fragrance.
The type of extraction method used is determined by the composition, volatility, and fragility of the plant being processed.
Steam distillation is the most popular method used to extract and isolate essential oils from plants. Steam is injected through the plant materials, which traps the plant's aromatic molecules in the water vapor. The steam is then transferred to a condenser and cooled, allowing the water to naturally separate from the plant's essential oils (which are then drawn off).
Cold Press Extraction
Cold press extraction is specifically used to capture citrus essential oils, which are extracted from the citrus fruit peel! As it sounds, the fruit as a whole is pressed by a machine to extract the juice and oil from the fruit. This mixture is centrifuged and allowed to separate naturally before the essential oil is collected.
CO2 extraction is exciting for its ability to product higher quality oils via a more sustainable process! Because CO2 extraction occurs at a lower temperature than steam distillation, the plant matter and the essential oils are undamaged by high heat and remain closer to the chemical composition of the original plant.
During this process, carbon dioxide is pressurized into a simultaneously liquid-gaseous state. The CO2 is then introduced into the plant material and acts as a solvent, pulling out and dissolving the essential oils into the liquid CO2. Finally, the mixture is brought back to normal pressure, causing the CO2 to evaporate and leave behind the essential oil.
The solvent extraction process is similar to steam distillation, however, instead of lifting the aromatic plant oils with water, a solvent such as hexane or ethanol is used. Solvent extraction is primarily used for plants that have low amounts of essential oil per plant volume, are largely resinous, or are too delicate for steam distillation. Solvent extraction also produces a more potent essential oil than any other extraction method.
Maceration and Enfleurage are other solvent extraction methods that use natural oils and fats to isolate the essential oils, although they are used much less frequently today than in ancient times.