The obtaining of essential oils – and their characteristics
The essential oil ascends with the vapor and when it cools down in the still, the oil and the water separate.
The essential oil is usually lighter than water and because it floats on top it can be easily extracted. The water, called ‘essential water’ (or Hydrosols), has some similar properties to those of the oil.
To obtain the concentrated essences the extraction method is usually used: the flowers are placed in a recipient which becomes a moving solvent that draws out all their aromas, colors, and wax.
This solvent is distilled continuously until obtaining a semi-solid substance that will be dissolved in alcohol and distilled again to obtain an essential oil of great quality that receives the final classification of “pure.”
The cold pressed (or expressed) is a method that is used for the obtaining of essential oils of the skin of a fruit by means of pressure, like in the case of the oils from citric.
When squeezing the skin (the pulp and the other fibers will have been extracted previously) you obtain an essential oil emulsion and watery liquid that will then be centrifuged and filtered. The citric essential oils are usually also called “essences.”
The oils “essentials” don’t resemble in anyway the fatty oils that we all know (as the olive oil, for example), because they evaporate completely without leaving a trace.
If you pour some essential oil drops on a paper a humid stain won’t take long to disappear, while the fatty oils always leave a greasy stain.
Essential oils characteristics
It can also happen that an essential oil leaves a stain with some tonality, because many of them are yellow, orange, brown or green in color.
Their consistency can go from being very liquid (lavender) to that of a syrup (siam benzoin).
The essential oils are not water-soluble, but they dissolve well in fatty oils, in cream, in whole milk, in honey and in alcohol. Their scent and their flavour are very intense and it is not a wonder; because to obtain a drop of rose oil it is necessary to use thirty flowers.
Some oils, as that of jara, are so dense that they do not even smell good and it is necessary to dilute them so that they are pleasant to the smell.