| > | | | | using a simple vacuum process, leaving only the |
| New methods of essential oil extraction are entering | | | | essential oil behind. The use of solvents in the |
| the mainstream of aromatherapy, offering new | | | | extraction process notwithstanding, absolutes can |
| choices in oils never before available. With the new | | | | have incredibly deep and complex aromas. The new |
| labels of 'CO2' and 'SCO2', along with the traditional | | | | high tech distillation methods include: Carbon Dioxide |
| 'steam' and 'hydro' distillations, 'absolutes', and 'cold | | | | and Supercritical Carbon Dioxide extraction. Both |
| pressing', a little education for the aromatherapy | | | | methods involve the use of carbon dioxide as the |
| enthusiast can go a long way in choosing the best | | | | 'solvent' which carries the essential oil away from the |
| essential oil for your needs. | | | | raw plant material. The lower pressure CO2 |
| Yes, even the age-old manufacture of pure essential | | | | extraction involves chilling carbon dioxide to between |
| oils is going high-tech. New modern distillation methods | | | | 35 and 55 degrees F, and pumping it through the |
| are entering the mainstream, offering wonderful new | | | | plant material at about 1000 psi. The carbon dioxide in |
| choices to aromatherapy enthusiasts and natural | | | | this condition is condensed to a liquid. Supercritical |
| health professionals. What are these new methods, | | | | CO2 extraction (SCO2) involves carbon dioxide |
| and more importantly, do they make better essential | | | | heated to 87 degrees F and pumped through the |
| oils? More therapeutic? Nicer smelling? Well, for most | | | | plant material at around 8,000 psi — under |
| varieties, the oils are simply different' — | | | | these conditions, the carbon dioxide is likened to a |
| not necessarily better'. For a few select oils, | | | | 'dense fog' or vapor. With release of the pressure in |
| these new techniques MAY produce a more healing | | | | either process, the carbon dioxide escapes in its |
| oil, and for others, the oils produced will truly add to | | | | gaseous form, leaving the essential oil behind. |
| the palate of the natural perfumer. Here's a quick | | | | These carbon dioxide methods have a couple of |
| look at all the major distillation methods in use | | | | advantages: Like steam distillation, there are no |
| today
| | | | solvent residues left behind, and the resultant product |
| A number of factors determine the final quality of a | | | | is quite pure. Like solvent extraction, there is no heat |
| steam distilled essential oil. Aside from the plant | | | | applied to the plant material or essential oil to alter it |
| material itself, most important are time, temperature | | | | in any way. The oil produced is very accurate with |
| and pressure, and the quality of the distillation | | | | respect to the original state of the plant. The CO2 |
| equipment. Oils used in therapeutic aromatherapy are | | | | methods also are the most efficient, producing the |
| really very chemically-intricate liquids; every oil | | | | most oil per amount of plant (one of the reasons for |
| consists of many individual molecular components | | | | the high cost of essential oils is the low yield of oil |
| which synergize to create the oil's overal biological | | | | from most plants — one ton of Rose petals |
| action and wonderful scent. Some of these molecules | | | | produces less than 1 pound of oil, for example). The |
| are fairly delicate structures which can be altered or | | | | efficiency of CO2 extraction is particularly important |
| destroyed by adverse environmental conditions. So, | | | | when rare or endangered plant species are involved, |
| much like a fine meal is more flavorful when made | | | | such as Indian Sandalwood oil — less of the |
| with patience, most oils benefit from a long, slow | | | | precious plant is needed to produce an equivalent |
| 'cooking' process. | | | | amount of oil. |
| The distillation vessel's temperature needs to be | | | | Last but not least is the expeller pressing of essential |
| carefully monitored and controlled so that the more | | | | oils from the rinds of ripe fruits like lemons, limes, |
| delecate volitile compounds are preserved. The same | | | | oranges and grapefruits. This method involves the |
| is true of the chamber's pressure. Lavender essential | | | | simple pressing of the rind at about 120 degrees F to |
| oil, for example, should not be processed at over 245 | | | | extract the oil. Little, if any, alteration from the oil's |
| degrees F and three pounds per square inch of | | | | original state occurs — these citrus oils retain |
| pressure (3 psi). Higher temperatures and/or | | | | their bright, fresh, uplifting aromas like that of smelling |
| pressures result in a 'harsh' aroma — more | | | | a wonderfully ripe fruit. |
| chemical than floral — and lessen the oil's | | | | CO2's, with some obvious advantages, are not |
| therapeutic effects. In addition, the duration of the | | | | always the best choice for a particular need. They still |
| distillation needs to be precisely monitored for each oil | | | | are the most expensive, despite their higher yields. |
| variety - not too long and not too short. This ensures | | | | The resultant product differs slightly compared to |
| all the important oil components are released, but the | | | | one produced another way — the oils |
| resultant oil is not 'overcooked', sometimes resulting | | | | produced by steam distillation of some plants may |
| in an unpleasant 'medicinal' scent. | | | | sometimes be found to have a more agreeable |
| Despite the drawbacks of aggressive processing, high | | | | aroma. Patchouli oil, for example, seems to benefit |
| temperatures and pressures are often used to | | | | from the steam distillation process by becoming a |
| produces large quantities of oil in a short period of | | | | little warmer and richer. Many other essential oils are |
| time. These oils are usually destined for use in | | | | quite effectively produced via steam distillation, with |
| cosmetic and processed food manufacturing, but are | | | | little alteration from the original plant state. Some |
| sometimes sold to final consumers as essential oils | | | | varieties do very well with the new cold extraction |
| for use in aromatherapy. These oils will be less | | | | methods; the resin oils like Frankincense and Myrrh |
| expensive, but are of limited therapeutic value, and | | | | may actually be more healing when made this way, |
| the difference is apparent when the aromas are | | | | and the oils of spices like Cardamom and Black |
| compared side-by-side. Some plants, and particularly | | | | Pepper can be more 'full bodied' in their scent. This |
| flowers, do not lend themselves to steam distilling. | | | | likely translates to greater therapeutic properties. |
| The volatile components are often too fragile, or too | | | | Producing essential oils of aroma-therapeutic grade is |
| difficult to extract using other means. These oils will | | | | skill requiring years of experience. Making an equisite |
| be produced as 'absolutes' — and while not | | | | essential oil of any variety demands experience and |
| technically considered essential oils they can still be of | | | | know-how at every step of the way, from growing |
| therapeutic value. Jasmine oil and Rose oil in particular | | | | and harvesting the plant material to closely monitoring |
| are delicate flowers who's oils are often found in | | | | the distillation itself. The making of a fine essential oil |
| 'absolute' form. | | | | relies far more on knowledge and experience than it |
| The processing of an absolute first involves the | | | | does on the particular extraction method. There are, |
| hydrocarbon solvent extraction of a 'concrete' from | | | | however, legitimate reasons to select one distillation |
| the plant material, a semi-solid mixture of typically | | | | method over another — some plants simply |
| 50% wax and 50% volatile oil. The concrete is again | | | | require a particular process to produce a fine oil, and |
| processed using ethyl alcohol (the same alcohol found | | | | the oil needed for a particular application may only be |
| in beer, wine, etc.) in which the wax is only slightly | | | | made by one process. In the end, as is often the |
| soluble. The volatile plant oil separates into the alcohol | | | | case in aromatherapy, your own sense of smell can |
| and this mixture is removed. The solvent is removed | | | | tell you which oil will work best for you. |