Experimental cookery

Directions for cooking meat usually state the time of cooking in terms of minutes per pound. At best this can only serve as a guide, for several factors may cause variation in the length of time required to cook a piece of meat. The only way of knowing when the interior of a piece of meat has reached a definite temperature and thus a definite stage of cookery is to insert something in the center of the meat by which the interior tem- perature may be read. For this purpose a thermometer or a thermocouple may be used. The easiest method for household use is the insertion of a thermometer into the meat. Two types of thermometers may be used : a right-angled thermometer with the temperature scale on the horizontal arm (see Fig. 23) ; or a very short tube- type thermometer about 6 or 8 inches long with the temperature scale on the upper half. The latter must be short to keep the top from touching the upper part of the oven, particularly the small gas ovens and many electric ovens. Thus the graduated scale is con- densed, which makes it more difficult to read. The short thermometer is preferable for small roasts of meat and for meat with soft fibers. The right- angled thermometer is suitable for beef roasts, ham, leg of veal, and lamb. It is convenient for taking temperatures of custards, cakes, and other foods, for it can be supported by the horizontal arm from a shelf in the oven. The following factors affect the time required to cook meat. (1) The cooking temperature. (2) Weight. Surface area. The shortest distance to the center of the thickest portion of the meat. (3) The stage to which the 234 MEAT meat is cooked — rare, or well done. (4) The composition of the meat. (5) The degree of ripeness. The cooking temperature. The higher the cooking temperature the more rapidly will a piece of meat reach a definite temperature, for with a higher temperature at the surface, the more rapidly heat will penetrate to the interior of the meat. As oven temperatures during the cooking of meat may vary many degrees, this factor causes a wide variation in the time required for cooking meat. Diagram A 10 Diagram G Diagram D Fig. 25. — To illustrate heat penetration in roasts and to show that the diameter does not increase in the same ratio as the weight. Weight. Surface area. Shortest distance to thickest portion of the meat. The time for cooking meat is often expressed in minutes per pound, but it is also a well-known fact that a heavy piece of meat of the same shape as one of light weight will require a shorter time per pound for cooking if the oven temperatures are the same. The reason for this can best be explained with the aid of a diagram. Suppose a cube 1 inch square weighs 1 ounce. It contains 6 square inches of surface area (see Fig. 25, diagram A), and the distance from the sides to the center {s — c in the figure) is ^ inch. If the cube is enlarged to 10 times its original size, dia- gram B, its weight is increased to 1000 ounces, its surface to 600 square TIME PER POUND 235