In the first part of the two-stage process of distillation, large stills - traditionally of copper - are filled with roses and water. The still is fired for 60–105 minutes. The vaporized water and rose oil exit the still and enter a condensing apparatus and are then collected in a flask. This distillation yields a very concentrated oil, direct oil, which makes up about 20% of the final product of the whole process. The water which condenses along with the oil is drained off and redistilled, cohobation, in order to obtain the water-soluble fractions of the rose oil such as phenethyl alcohol which are a vital component of the aroma and which make up the large bulk, 80%, of the oil.