The oil from a small amount of cream is easiest to obtain in the following way. You need to take a two-liter plastic bottle, cut the top with a tube (height of cut 60 mm). This cut from the bottom to remove another 10 mm, so it is easily included in the remaining part of the bottle. Cut off the neck need to make six holes with a diameter of 7 mm each; and the same size hole in the tube to insert the rod, the thickness of which corresponds to this hole. The end of the rod to attach the wire to the neck of the top and bottom. Pour ripened cream into the bottle, drop it in the terminal with the neck. This pest, resembling a piston in the cylinder, effortlessly raised and lowered in a smooth bottle. Pretty quickly transparent plastic prompt working that cream turned into butter and buttermilk.