This extractive technique is based on the volatile physical properties of essential oils, which means that oil is easily vaporized and carried away by the water vapor.
The aromatic plant to be distilled can be used in both the fresh and dried states. A fresh plant harvested at the right time of day during what is called the balsamic time, or the time when the concentration of the active ingredients of the plant is highest, is ideal. The time elapsed between harvesting and distillation must be the shortest possible to avoid the alteration and the dispersion of essential oil in the time of conservation.
Before putting the plant inside the distiller, the plant must first be clean of insects, infesting plants, and material not suitable for distillation.
The passage of water vapor through the plant material is generated by boiling water. In this process the plant’s cell walls become more permeable until the cell walls break and release the essence which, being volatile, becomes vaporized.
The mixture of water vapor and plant essence becomes condensed in a cold coil circulated by cold water and brought back to the liquid state, becoming separated as essential oil and distilled water.
The essential oil settles on top of the water because of the oil’s lower density.
The obtained essence must undergo a process of purification before being utilized. This consists of eliminating the unnecessary, irritating, and unpleasant components.
The gathered water is an aromatic water because it contains a small percent of dissolved essential oil, which gives it the fragrance of the distilled plant. It can be utilized in cosmetics, in the kitchen, and also as water used in ironing laundry.
The essential oils obtained through distillation are widely used in perfumeries and phytocosmetics, in the food industry as flavorings, and for aroma therapy.