White sesame seeds are cleaned, soaked and dried, then roasted and pressed. Only the first pressing of the oil is used; only 12 kg of oil is obtained from 40 kg of sesame seeds, which corresponds to a yield of 30%. After pressing, the oil cools down very slowly. Hot water is then added, stirred and left to stand for a month to separate impurities and suspended matter. The sesame oil is then extracted, heated in a container over a wood fire and filtered through Japanese paper (washi) before bottling. In traditional and modern Japanese cuisine, sesame oil is used for cooking and to flavour dishes.