Keep the curd gently stirred up and floating in the whey and do not allow it to lie on the bottom of the vat long enough to pack firmly together, stirring once in a while until by smell and taste (if not also by acid or hot iron tests) it appears to be sufficiently fermented for the whey to be drawn, a condition that can only be learned by experience. This will be about two or three hours from the time the rennet is added. [Illustration: Diagram of lever press ] [Illustration: Combined screw and lever press ] Draw the whey and press more out of the curd with the hands. Let the curd mat and break it up alternately several times; finally crumble and pulverize it and keep it stirred with the hands, adding salt at the rate of three to four ounces to the curd from 100 lbs. of milk and continuing the stirring until the curd is cooled down to below 80°, when it should be packed into the hoop and put to press. This salting and cooling may take another hour. The hoop may be made of wood or heavy tin of any size desired, with a loose follower of wood. The sides and bottom should be perforated to allow the whey to escape. Or it may be a cylinder without top or bottom, placed on a corrugated piece of board. Line the hoop with cheese-cloth before putting in the curd. [Illustration: Upright factory and dairy cheese press ] For pressing, a home-made lever-press, as outlined in the diagram, may be made of a plank or bar, one end of which (_C_), is stuck under a piece of a board nailed on the wall while at the other end a weight (_K_) is applied which may be moved in and out to regulate the pressure. The hoop is placed under the plank at the fulcrum (_K__{1}) near the wall. If a compound lever-press or a screw-press is available it is better. It is important that the pressure is applied straight so as to make the cheese even and not one side lower than the other. Begin with light pressure and increase it gradually every hour until at night the full pressure is applied. After an hour take the cheese out and turn it in the hoop, then return it to the press and at night apply full pressure. The next morning take it out and weigh it and place it on the shelf to cure in a room of moderate temperature, turning it every day. After a couple of weeks it may be removed to a cool cellar and rubbed with grease. In two to three months it should be sufficiently matured for consumption. OTHER TYPES OF HARD CHEESE MADE WITH RENNET [Illustration: A variety of domestic and foreign cheese made at the dairy school of the University of Wisconsin ]