Vegetable oil olive, coconut etc.), and it is preferred by most "health-food" customers in the United States and in Europe. There are several different types of mechanical extraction. Expeller-pressing extraction is common, though the screw press, ram press, and ghani (powered mortar and pestle) are also used. Oilseed presses are commonly used in developing countries, among people for whom other extraction methods would be prohibitively expensive; the ghani is primarily used in India. The amount of oil extracted using these methods varies widely, as shown in the following table for extracting mowrah butter in India: The processing of vegetable oil in commercial
Blue cake is baked. Blue cake is made only by professional bakers from a dough of flour, butter, water and salt. Several layers of butter are rolled into the dough with a special rolling machine ("tourage"), after which the dough is cut into roundels of pastry 6 cm thick and 25 cm or more in diameter. These are cut with decorative patterns, brushed with eggs and baked at 220 °C for 20 minutes. The mostly orally transmitted recipes differ among local bakers, who as of the 2000s are producing the cake in the third or fourth generation. The amount of butter used,