+100. Curd knives.+--For cutting curd, special knives have been devised (Fig. 11). They consist of series of parallel blades fixed in a frame to make cuts equidistant. The blades run vertically in one, horizontally in another. They are spaced according to the demands of the variety of cheese to be made. Wires stretched in a frame take the place of blades in some makes of curd knife. [Illustration: FIG. 11.--Blade and wire curd knives: horizontal, perpendicular, horizontal, perpendicular.] +101. Heating or "cooking."+--Curdling by rennet has already been shown to be markedly hastened by moderate heating. After the coagulum or curd is formed, the making process may be completed without the application of further heat, as in Neufchâtel, Camembert and related forms (Fig. 12) and in some practices with Limburger. In other forms and especially in the hard cheeses in which cutting of curd is a prominent part of the process, the curd after being cut is reheated or "cooked." The cooking process hastens the removal of the whey, thus shortening the time required to reduce the water-content of the mass to the percentage most favorable for the type of cheese desired. The process also produces marked changes in the physical character of the curd mass. With the rise in temperature the casein becomes elastic first, then approaches a melting condition and assumes a tough, almost rubbery consistency. The final texture is the result of the combination of the amount of rennet added, the temperature, the acidity reached during the process, and the final water-content of the mass. [Illustration: FIG. 12.--The heat relation. See pages 77 and 87.] +102. Draining+ (including grinding, putting into hoops or forms and pressing).--The reduction of the water in the curd begins almost as soon as the curd becomes firm. It is aided by cutting or breaking, by the retention of the heat applied before renneting and by the secondary heating or cooking used in making certain groups of cheeses. In many varieties special apparatus is provided in the form of draining boards, draining racks or bags to hasten the removal of the whey as fast as it separates. The draining process continues until the cheese has reached its final form and weight. The intervening process of matting in the Cheddar group involves a combination of a souring process with the removal of whey, during which the cubes of curd become fused into semi-solid masses. If such masses are formed, they must be ground up before the cheese can be given its final form in the hoop. The draining process, therefore, may take any one of many forms varying from the direct transfer of freshly formed curd into hoops in which the entire draining process is completed, to an elaborate series of operations which end in pressing curd drained to approximately its final condition before it is placed in the hoop.