Essential oil is any concentrated, hydrophobic liquid containing volatile aroma compounds from plants. il can be extracted from any part of the plant from petals and leaves, roots, seeds and rinds. Essential oils are generally extracted by distillation. Most essential oils are extracted by steam. Other processes include expression, or solvent extraction. They are used in perfumes and cosmetics, for flavoring food and drink, and for scenting incense and household cleaning products. There are many ways in which essential oils are extracted. The vast majority of true essential oils are produced by distillation. Distillation is a method of separating chemical substances based on differences in their volatilities in a boiling liquid mixture.

Distillation usually forms part of a larger chemical process, and is thus referred to as a unit operation. Steam distillation, the most common method of essential oil production, involves the flow of steam into a chamber holding the raw plant material. The steam causes small sacs containing essential oil to burst. Steam distillation uses an outside source of steam which pipes the steam into the distillation unit, sometimes at high pressure. The steam passes through the aromatic material, and exits into the condenser. Another method is essential oil extraction is Pomades. Pomades are produced using a process known as enfleurage, which is seldom done today. Freshly cut flowers are laid upon a layer of fat. The final step would be an alcohol extraction of the fragrance-saturated fat to produce the pure absolute or perfume.

Essential Oil Extraction - Enfleurage is the method by which flower essences such as Jasmine, Rose, which are more delicate and difficult to obtain are extracted. Flowers or petals are crushed between wooden framed, glass trays smeared with a greasy animal fat until the fat is saturated with their perfume. Other method is cold pressing. This method is typically employed for citrus oils. What is done is simply the rind is pressed under the conditions of a high temperature, about 120 degrees Fahrenheit, and the oils are removed. Mechanical pressure is used to force the oils out. The oils extracted contain water, but this water will, in time, evaporate, leaving just the essential oils. The downside of using this extraction method is that the cold pressed oils spoil more quickly than those extracted using other methods.

Pressing is a simple method of squeezing out literally, essential oils from the rinds and peel off ripe fruit such as orange and lemon into a sponge. Solvent extraction is used in combination with distillation. A hydrocarbon solvent is put in with the plant material and dissolves the essential oil. The resulting solution is then filtered and put through a distillation process that concentrates the oil to produce a resin, or resinoid. The remaining substance is a combination of wax and essential oil and is called “concrete. The most modern method of extracting essential oils is the CO2 and SCO2, or carbon dioxide and supercritical carbon dioxide, method. This method uses the ‘solvent’ carbon dioxide to carry the essential oils out of the plant. Another method for extracting essential oils is one that is reserved called absolutes.