In Bulgaria, the rose blossoms (Rosa damascena) begin to bloom around the third week of May and will continue for three or four weeks, depending upon climatic conditions. The yield of oil can be dramatically affected by the prevailing weather conditions - for example during very hot and dry weather the harvest may last only two weeks and the yield of the oil is lowered due to loss by evaporation. Conversely, during mild and humid weather the harvest time can be extended whilst at the same time increasing the oil yield.

Under normal conditions, harvesting commences as soon as the flowers begin to open and continues until all the roses have been gathered. The flowers are still picked by hand, where they are nipped off just below the calyx (the green, outer protective cover). The flowers are gathered at daybreak and placed into baskets, and then transferred to sacks for transportation to the distilleries.

From the minute harvesting begins it becomes a race against time, for all flowers must be picked before 9.00 a.m. whilst the dew is still on the flowers and the sun is low. Once collected, the harvest is then transported to the distillery as quickly as possible since the picked flowers will begin to deteriorate immediately as precious volatile oil begins to evaporate due to the heat of the sun. This in turn of course will lower the yield of the crop and push up the price of production.

Modern stills are made of copper and are heated with an open wood fire from below. The roses can not be distilled in the usual way by directly injecting steam, because the petals compact to form a large mass that the steam can not penetrate. Therefore the distillation techniques have been refined in various ways to overcome this problem.