Have you ever wondered how essential oils are produced?
Most of them come to us through water distillation. The plant, be that wood, leaves, flowers etc is cut up into small size pieces and the water is brought up to boiling point. The essential oils condense out at a different temperature just as alcohol does in Whisky production and so can be separated out. Sometimes this process is repeated once or twice, producing a lower grade essential oil each time.
One exception to this technique is the citrus oils which are produced by cold pressing the skin of the fruit or for a higher quality of oil, sometimes the zest. The essential oil will then float on top of the water from the pressing and can be taken off.
There are machines which let one distil oils oneself but they are beyond my price range so I haven’t tried them out yet.
Infused oils however can easily be made by anyone. You take the herb in question, macerate it and then add it to the carrier oil and if keeping at room temperature strain it after three or four weeks. The process can be speeded up by putting the jar containing the mix in a water bath at around 60C for four hours. Some herbs with a high water content need a short drying period first to prevent decomposition taking place during the process, especially if doing it over four weeks.
Herbs I have done this with include Melissa, Rosemary and Lemon Balm. The herbs all come from my garden or allotment here in Cambridge.