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| Extracting Oils from Herbs |
Answered by: Conrad Richter
Question from: Denise Rowe
Posted on: January 22, 2002
How are oils extracted from herbs for use in that form?
Herbal oils are extracted or made in a variety of ways depending on the nature of the oil. Aromatic herbs such as thyme, lavender, and anise possess volatile oils, oils that escape into the atmosphere readily, which is why you can smell them easily. Because the oils are volatile they are easily extracted with heat, usually in the form of steam. The steam-oil vapour is cooled and the oil separates from the water and is then collected. There is a chapter on oil distillation of herbs in "Richters Third Commercial Herb Growing Conference" which is available in the book section of our online catalogue.
Some oils are not as volatile and are more efficiently extracted by other means. Seed oils such as olive, flax, sunflower and almond are pressed and then separated.
Another way to extract oils is to use organic solvents such as benzene. These methods are often used for herbs that are more like resins than liquid oils.
Many oils used for fragrance or medicine are oil-based extractions of the herb. For example, St. Johnswort or comfrey oils are made by steeping fresh or dried herbs in a base oil such as almond oil. The compounds extracted from the herbs when steeped in oil are different from those extracted in water (as you would have when you make a tea or decoction). In the case of St. Johnswort and comfrey oils used as emollients for skin application, the oil also serves as an ideal delivery base for the medicinal components from the herbs.
When buying oils it is important to know the distinction between "essential oils" and what are called "fragrance oils." The former are the pure votatile oils extracted typically by steam distillation already described. The latter are oils that have been diluted by a neutral carrier oil. Fragrance oils are useful when the pure essential oil is just too strong to use in the pure form. It is surprising how strange and how strong pure oils can be, and in fact, in some case pure essential oils can be dangerous to use.
Also, where do I find the book lists, e.g. Skin products?
In our online catalogue (http://www.richters.com) go to the catalogue directory page where you will see links to pages that index the books alphabetically. Margaret Dinsdale’s book, "Skin Deep," is an excellent resource for making one’s own personal body care products using herbal oils.