Aromatherapy and natural beauty have been popular recently, and so have essential oils, leading some of our patrons to wonder: where do they come from, exactly?
Essential oils come from different plants, and there are several methods of extracting them, according to Essential Oils: Natural Remedies which is published by Althea Press. The method used can depend on the plant. Citrus oils are cold-pressed, which means the rind is put in a press at 120 degrees Fahrenheit.
Ginger, frankincense, and myrrh are some of the oils typically extracted through CO2 distillation. There are two methods of CO2 distillation: cold and supercritical. Both involve passing carbon dioxide through the plant matter, but in cold distillation, the CO2 is cooled to between 35-55 degrees Fahrenheit, and in supercritical, it’s heated to 87 degrees Fahrenheit.
Steam distillation is a common method and involves passing steam through the plant to collect the oils and then condensing the steam and separating the oil from the water. The water left over from this process is called hydrosol and can be used in scents and beauty products.
Chemicals such as methylene chloride (which can also be used as a paint stripper, degreaser, and component in drinking bird toys and bubble lights, among other things) can be used in place of water or CO2. After the oil has been extracted, the remaining solvents are removed, but tiny traces may remain.
Finally, there’s the very old method of enfleurage. Plants (typically flowers, as suggested by the name) rest in a bath of warm fat or fatty oil. The fatty oil absorbs the essential oils from the flowers. Once it’s saturated, alcohol is added, which absorbs the essential oils from the fat or fatty oil and then evaporates, leaving only the essential oils behind. Like hydrosol, the fat remains scented and can be used in other products.