Many plants and herbs are used to make essential oils.
The extraction and production of aromatherpeutic grade essential oils is done in several ways, and requires years of experience. There are many steps involved beyond just growing and harvesting, and the knowledge of the producer plays a key role in the successful end product. The selection of one distillation method over another is many times driven by the make up of the plant source. Some plants are more easily processed by one method instead of another.
Instructions
Extraction Methods
1. Distillation: Most essential oils are produced using this method and more specifically for leaves, flowers, seeds, roots and stems. Water is heated to produce steam, which rises and gently simmers the contents. The heat causes the essential oils to be released by the plant. As the water evaporates, the oils rise to the top where they can be collected.
2. Cold Pressing: Many citrus oils are produced using this method. Only the finest plants should be used to obtain essential oils by cold pressing the rind or peel. This process is also called scarification. The rind is scored, and when pressed, the oils are captured.
3. Carbon Dioxide Extraction: This is a relatively new method of extraction that uses the state of carbon dioxide when it acts as both a gas and liquid after it is subjected to high pressure. Once it returns to normal pressure and temperature, carbon dioxide reverts to gas and evaporates, leaving no solvent residue. The equipment used for this method can be quite expensive, but the amount of oil produced is greater than other methods, thus making some oils more widely available. Also, because carbon dioxide extraction is gentler on plants, the result is an oil with exceptionally true aromas.
4. Steam Distillation: Historically, this is the most common method of extracting essential oils. During distillation, steam runs through the plant material. The cells of the plant are broken down, and the steam carries the essential oil to a cooling area where the essential oil and water are separated.
5. Which is the best method? It varies by plant which method will produce the best results without either destroying the plant or the oil itself. Some plants simply require a particular process to produce a fine oil. Ultimately, it is the user's sense of smell which will lead them to the best oil production.
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