| The newest high-tech methods of making | | | | 50% wax and 50% volatile oil. The concrete is again |
| aromatherapy-grade essential oils have some great | | | | processed using ethyl alcohol (the same alcohol found |
| advantages, but with a steeper price. Are they | | | | in beer, wine, etc.) in which the wax is only slightly |
| worth it? It may be up you your nose to find out... | | | | soluble. The volatile plant oil separates into the alcohol |
| Aromatherapy Goes 'High Tech'New methods of | | | | and this mixture is removed. The alcohol is then |
| essential oil extraction are entering the mainstream of | | | | evaporated and the result is an almost pure plant |
| aromatherapy, offering new choices in oils never | | | | extract — depending on the care taken in the |
| before available. With the new labels of 'CO2' and | | | | evaporation process, sometimes 2% or less of the |
| 'SCO2', along with the traditional 'steam' and 'hydro' | | | | ethyl alcohol may remain. The use of solvents in the |
| distillations, 'absolutes', and 'cold pressing', a little | | | | extraction process notwithstanding, absolutes can |
| education for the aromatherapy enthusiast can go a | | | | have incredibly deep and complex aromas. |
| long way in essential oil selection. Is one process | | | | CO2's and SCO2'sAnd now for the most modern |
| better than another? Does one produce a nicer | | | | technologies, Carbon Dioxide and Supercritical Carbon |
| smelling oil, or one with greater aromatherapeutic | | | | Dioxide extraction. Both methods involve the use of |
| value? It turns out that essential oil production, like | | | | carbon dioxide as the 'solvent' which carries the |
| winemaking, is an art form as well as a science. The | | | | essential oil away from the raw plant material. The |
| value of the newer processing methods depends | | | | lower pressure CO2 extraction involves chilling carbon |
| greatly on the experience of the distiller, as well as | | | | dioxide to between 35 and 55 degrees F, and |
| the intended application of the final product. Each | | | | pumping it through the plant material at about 1000 |
| method is important, and has it's place in the making | | | | psi. The carbon dioxide in this condition is condensed |
| of aromatherapy-grade essential oils. | | | | to a liquid. Supercritical CO2 extraction (SCO2) |
| Steam and Hydro DistillationSteam distillation, the | | | | involves carbon dioxide heated to 87 degrees F and |
| most common method of essential oil production, | | | | pumped through the plant material at around 8,000 |
| involves the flow of steam into a chamber holding | | | | psi — under these conditions, the carbon |
| the raw plant material. The steam causes small sacs | | | | dioxide is likened to a 'dense fog' or vapor. With |
| containing essential oil to burst. The oil is then carried | | | | release of the pressure in either process, the carbon |
| by the steam out of the chamber and into a chilled | | | | dioxide escapes in its gaseous form, leaving the |
| condenser, where the steam once again becomes | | | | essential oil behind. |
| water. (Hydro-distillation is a similar process where the | | | | These carbon dioxide methods have a couple of |
| plant material is boiled, with the resultant steam being | | | | advantages: Like steam distillation, there are no |
| captured and condensed). The oil and water are then | | | | solvent residues left behind, and the resultant product |
| separated; the water, referred to as a 'hydrosol', can | | | | is quite pure. Like solvent extraction, there is no heat |
| be retained as it will have some of the plant essence. | | | | applied to the plant material or essential oil to alter it |
| Rose hydrosol, for example, is commonly used for it's | | | | in any way. The oil produced is very accurate with |
| mild antiseptic and soothing properties, as well as it's | | | | respect to the original state of the plant. The CO2 |
| pleasing floral aroma. | | | | methods also are the most efficient, producing the |
| A number of factors determine the final quality of a | | | | most oil per amount of plant (one of the reasons for |
| steam distilled essential oil. Aside from the plant | | | | the high cost of essential oils is the low yield of oil |
| material itself, most important are time, temperature | | | | from most plants — one ton of Rose petals |
| and pressure, and the quality of the distillation | | | | produces less than 1 pound of oil, for example). The |
| equipment. Essential oils are very complex products; | | | | efficiency of CO2 extraction is particularly important |
| each is made up of many, sometimes hundreds, of | | | | when rare or endangered plant species are involved, |
| distinct molecules which come together to form the | | | | such as Indian Sandalwood — less of the |
| oil's aroma and therapeutic properties. Some of these | | | | precious plant is needed to produce an equivalent |
| molecules are fairly delicate structures which can be | | | | amount of oil. |
| altered or destroyed by adverse environmental | | | | Cold PressingFinally, there is the 'cold pressing' of |
| conditions. So, much like a fine meal is more flavorful | | | | citrus oils from the peels of fruit, as is done with |
| when made with patience, most oils benefit from a | | | | Bergamot, Orange, Lemon, and the like. This method |
| long, slow 'cooking' process. | | | | involves the simple pressing of the rind at about 120 |
| The temperature of the extraction chamber cannot | | | | degrees F to extract the oil. Little, if any, alteration |
| be too high, lest some components of the oil be | | | | from the oil's original state occurs — these |
| altered or destroyed. The same is true of the | | | | citrus oils retain their bright, fresh, uplifting aromas like |
| chamber's pressure. Lavender, for example, should | | | | that of smelling a wonderfully ripe fruit. |
| not be processed at over 245 degrees F and three | | | | ConclusionCO2's, with some obvious advantages, are |
| pounds per square inch of pressure (3 psi). Higher | | | | not always the best choice for a particular need. |
| temperatures and/or pressures result in a 'harsh' | | | | They still are the most expensive, despite their higher |
| aroma — more chemical than floral — | | | | yields. The resultant product differs slightly compared |
| and lessen the oil's therapeutic effects. Also, the | | | | to one produced another way — the oils |
| extraction period must be allowed to continue for a | | | | produced by steam distillation of some plants may |
| certain period of time in order to flush ALL the oil's | | | | sometimes be found to have a more agreeable |
| components from the plant, as some are released | | | | aroma. Patchouli, for example, seems to benefit from |
| more quickly than others. | | | | the steam distillation process by becoming a little |
| Despite the drawbacks of aggressive processing, high | | | | warmer and richer. Many other essential oils are quite |
| temperatures and pressures are often used to | | | | effectively produced via steam distillation, with little |
| produces large quantities of oil in a short period of | | | | alteration from the original plant state. Oils from other |
| time. These oils are usually destined for use in | | | | plant species do seem more 'complete' with CO2 |
| cosmetic and processed food manufacturing, but are | | | | processing, with Frankincense and most of the 'spice' |
| sometimes sold to final consumers as essential oils | | | | oils being good examples where a little something |
| for use in aromatherapy. These oils will be less | | | | special is present in the aroma. |
| expensive, but are of limited therapeutic value, and | | | | Producing essential oils of aromatherapeutic grade is |
| the difference is apparent when the aromas are | | | | skill requiring years of experience. It takes the work |
| compared side-by-side. | | | | of a dedicated artesian at every step, from growing |
| AbsolutesSome plants, and particularly flowers, do | | | | and harvesting to fine-tuning the distillation process, |
| not lend themselves to steam distilling. They are too | | | | to produce a truly fine oil. The making of a fine |
| delicate, or their fragrance and therapeutic essences | | | | essential oil relies far more on knowledge and |
| cannot be completely released by water alone. These | | | | experience than it does on the particular extraction |
| oils will be produced as 'absolutes' — and while | | | | method. There are, however, legitimate reasons to |
| not technically considered essential oils they can still | | | | select one distillation method over another — |
| be of therapeutic value. Jasmine and Rose in | | | | some plants simply require a particular process to |
| particular are delicate flowers who's oils are often | | | | produce a fine oil, and the oil needed for a particular |
| found in 'absolute' form. | | | | application may only be made by one process. In the |
| The processing of an absolute first involves the | | | | end, as is often the case in aromatherapy, your own |
| hydrocarbon solvent extraction of a 'concrete' from | | | | sense of smell can tell you which oil will work best for |
| the plant material, a semi-solid mixture of typically | | | | you. |