Essential Oils

Most essential oils are prepared by distillation, in which the volatile components come off the still. Unlike essential oils, an absolute is prepared by extracting aromatic compounds with hexane (essentially gasoline) and then removing the hexane either through simple evaporation or vacuum evaporation. Since there’s no hexane left, it doesn’t pose a problem.

Some essential oils are prepared with simple extraction. Lemon zest, for example, can simply be pressed to extract its oil.

The ne plus ultra of aroma extraction is enfleurage. Flower petals are arranged on trays of hard fat, traditionally tallow but nowadays usually hydrogenated palm oil. After several hours or overnight, the petals are replaced with fresh ones. The process continues until the fat is completely saturated with the aroma of the flowers. The aroma is then extracted from the fat with ethanol (drinkable alcohol) and the ethanol evaporated to leave only the exquisite enfleurage.