I've always been curious as to how oils are produced. I know they come from a plant and are distilled and the oil is seperated from the hydrosol. That is about all I could say when I first started wondering.
In my research I have found that there are actually many different ways to create essential oil.
Maceration, an ancient method which impregnantes fat with floral scents and the fat is used in things like ancient Egyptian pomades and cosmetics.
Enfleurage is the prcess of soaking the plants in oil and then heating it until the plant's essential oil is in the carrier.
Expression is used exclusively for citrus oils to press out the oils from the peels.
Solvent extracts is used for sensitive fragrances with low yeilds. Its a complicated process involving low boiling point solvents and grain alcohol.
Synthetics...made in a lab...
Steam distillation is the most common form.
Below is a series of videos from YouTube about how to creat LAVENDER essential oil, in keeping with this month's herbal theme.
Stills can be bought at copperstills.com
Buying a still can be a bit pricy.
For home use, if you're handy or have a handy friend, there are a lot of sites that explain how to create your own still using items found at your local Lowe's.