AnaI, is it possible you are confusing essential oils and infused oils?
Essential oils are a volitile part of plants, often responsible for their flavor and aroma. As Luc explained, they are extracted from the plants using various distilation methods.
This is not, btw, a tabletop operation that you can do at home.
Infused oils, on the other hand, are often used for culinary purposes. For those, a flavoring agent is mixed with an oil and allowed to sit for various time periods. The oil extacts the flavors, which get infused through it.
For instance, I recently made a mint-infused oilive oil for one of Nino Graziano's great recipes. This is one of his basic oil infusions:
1 dl (scant 1.2 cup) extra virgin olive oil
1 bunch fresh mint
Puree the mint leaes with the oil in a food processor or blender. Strain through a fine-mesh sieve (discarding the solids) and reserve the oil.
Note that mint infuses quite readily, so it doesn't have to sit for an length of time. On the other hand, a tangerine-infused oil he also makes has to macerate for 6 days.
Infused oils are also an integral part of herbal medicine. The basic balm I make, for instance, uses six different herbs, each infused seperately into the oil. But the process is the same, whether you are making medicine or making dinner.  |