Peppermint oil is extracted from the whole plant above the ground just before flowering. The plant chopped in to a size of 1-3cm, and placed on a grid which is located at a certain distance above the level of water which fills the bottom of the kettle. The water is vaporized indirectly by steam flowing in a pipe coil submerged by the water. The water and the distilled oil coming from the evaporator vessel are recovered in a separate water cooled condenser. The mixture flowing out of the condenser is separated by decantation. The distilled water, which may contain some oil, shall be sent to distillation tank in which the oil is extracted.
The production process of peppermint oil has no impact one environment. The solid waste (straw) from steam distillation processes dried and transported to compost production or can be used as energy source.