Essential Oil Extraction Methods Explained

There are principally four methods that companies use to extract essential oils. These procedures are diverse due to the plant or flower that is targeted for extraction, so it is necessary to utilize varying methods based on what type of thing the oil is retrieved from. The first method that is used, and probably the most common, is steam and hydro distillation. This method involves the plant, from which the oil is being extracted, to be placed in a large chamber. Within this chamber, the plant is subjected to steam that fills the entire chamber. Once filled, the steam travels through the interior of the plant and picks up the oils that are hidden inside. The steam continues upward until it travels to a condenser, where the steam is cooled and is consequently turned back into water. As well, the oil that is captured by the steam is equally returned to its former state. But, now it is outside of the plant and ready for production.

The oil and water are then separated from each other and then the oil can be used. This oil is called ‘hydrosol’. The quality of the oil extracted by this means relies on several factors that are determined through the process, such as, pressure, temperature and time. These factors can ‘make or break’ the quality of the product. This is because a plant’s ‘essence’ is found in these oils. So, because essential oils on a molecular level possess a delicate bond, to where, if any of these factors are not properly met, these bonds will break up and the ‘essence’ of the plant will not be preserved. Ultimately, steam and hydro distillation is very much similar to the activity of cooking a meal. If one does not follow the instructions and makes sure that all of the conditions that are prescribed in the manual are met, than the meal’s ‘tastiness’ will suffer as a result. This is why it is important for the extracting methods of oils by distillation be at just the right temperature, done in a certain amount of time and with the right amount of air pressure in the chamber where it is achieved.

Another method for extracting essential oils is one that is reserved for what are called absolutes. These are plants or flowers that are either too delicate to undergo the distillation process or their essential oils are not released by way of it. Instead another method must be employed. One method of dealing with these delicate sources is by way of a hydrocarbon solvent extraction of a ‘concrete’ from the plant. This ‘concrete’ is a 50 percent semi solid mixture of wax and another 50 percent semi solid mixture of volatile oil. This mixture is again processed in the same manner as ethyl alcohol (the same as in liquors) to where the wax is transformed into a slightly soluble state.

Fortunately, the volatile plant oil is removed from the plant by the alcohol. Once out of the plant, the alcohol is dissolved and the essential oils are left behind for harvesting. This process miraculously looses only 2 percent of the plant’s essential oils in the extraction, so that, essential oils extracted like this can be very potent and strong. Plants that are often extracted in this way are jasmine and rose.

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. The lower pressure carbon dioxide method involves cooling the gas to between 55 and 35 degrees F and pumping the chilled CO2 through the plant at about 1000 psi. In this state the CO2 is in liquid form and moves quite freely through the plant. By using the supercritical carbon dioxide method, the carbon dioxide is heated to 87 degrees f and is pumped through the plant at 8000 psi. The CO2 is in gas form and travels through the plant extracting the oils. And like the CO2 method, when it is cooled the oil is harvested. This method is more efficient than both the distillation method and that used for absolutes because unlike the former there is no heat applied to the plant itself, and unlike the latter, there is no residue left behind after the process.

The final method is that of 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. These are the four ways that essential oils are extracted.