A single drop of an essential oil can be potent enough to have powerful health benefits. Micro-droplets of oils are stored within a plant’s glands. After these droplets are diffused through the gland walls, they spread out over the plant’s surface and then evaporate, filling the air with a pleasant aroma.

Plants with the strongest scents are usually found in tropical regions where there are higher temperatures, which causes plants to produce more biogenic volatile organic compounds while also extending the growing period throughout which their fragrant compounds are generated. Typically, it takes many pounds of plant material to produce a small amount of essential oil. In the case of Rose Oil, 65 pounds of rose petals are required to make only 15 mL of oil.

The following methods are the ways to extract essential oils: Enfleurage, Expression, Steam Distillation, Solvent Extraction, Carbon Dioxide Extraction, Fractional Distillation and Percolation, Phytonic Process, Maceration, Mechanical Pressing, and Distillation.

 

EXTRACTION METHOD's PROCESS
Enfleurage Delicate plant parts like flowers, roots, and leaves are soaked in fatty oils to extract their essential oils
Expression A rotating mechanical device with spikes punctures the fruit rind to release its essential oils. This method is also called "Cold Pressing." It is specifically meant for citrus essential oils (Lemon, Bergamot, Orange, etc).
Steam Distillation A current of steam is injected into the still containing botanical material, usually at high pressures and temperatures.
Solvent Extraction One of the components of botanical material dissolves in a particular liquid (solvent) and the non-volatile components, such as waxes and pigments, are separated/removed by filtration. This method is also called "Liquid-liquid Extraction." It emcompasses Enfleurage, Maceration, and Carbon Dioxide Extraction.
Carbon Dioxide (CO2) Extraction Pressurized CO2 turns into a “supercritical” liquid that is pumped into a chamber containing plant material. Despite being a gas it has liquid properties, which allows it to act as a solvent that pulls out the plant matter’s essential oils.
Hydro-Diffusion (Hydrofusion) Extraction This method is similar to steam distillation except that the steam enters through the top of the chamber rather than the bottom. The plant material lies on top of a grill, so the steam “percolates” down through the plant material, much like coffee passes through a filter. This method is also called "Percolation."
Phytonic Process This method uses non-chlorofluorocarbons (non-CFCs) as a solvent. The oils produced are called Phytols. The extraction occurs at or below room temperature, which means the oil is not degraded by high temperatures. These oils are pure and as close to the natural plant properties as possible. This method is also called "Florasol Extraction."
Maceration A solvent (Menstruum) is added to cut/ground/crushed plant material and the mixture is allowed to stand for a certain period of time. The liquid is strained and the solid residue is pressed for any remaining liquid. Both strained and expressed liquids are mixed then filtered.
Oil Soak Plant material is soaked in a carrier oil. After 2 weeks, the solids are strained the remaining infused oil is the final product.
Water Distillation Plant material is submerged in water that is heated until the plant material becomes soft. The oil vapors rise, enter a condensation chamber, and cool off. Here, the steam becomes water again, but the vapors become the oil. The oil is then separated from the water component, which becomes the “floral water” (hydrosol).

 

The most popular extraction method for essential oils is steam or water distillation of the roots, bark, stems, leaves, flowers or other parts of a plant. With the aid of steam, this process separates the plant’s healing oil-based compounds from the water-based compounds to produce a single, concentrated aromatic oil.