Stews should be covered and should not be cooked in too much water, as the juices are weakened and too great an amount of flour is necessary to thicken them, thus rendering them less digestible. They are cooked slowly at low temperature (130 to 160 F.) and so do not need much water.
If properly made, stews are both economical and nutritious, as no nutrition is lost in evaporation and all material save bone or gristle is utilized.
Baking. Meats, when baked, are covered with a crust, either of batter or pastry. This prevents the escape of the volatile matters, and meats thus cooked are richer, especially if they contain much fat. For this reason they are seldom suitable for invalids, or for those who have any form of stomach trouble.
Steaming. This method of cooking is applied mainly to vegetables, puddings, etc. Steamed puddings and dumplings are softer than when baked. The cover must not be removed during the time of steaming, or they may become soggy, hence less digestible.
Frying. This is the least desirable method of cooking. If a lighted match is placed near the smoke of superheated fat the fat will catch fire, showing that it is volatilizing, or being reduced to a vapor.
The extreme heat liberates fatty acids which soak into the food and render it difficult of digestion. It is wise not to employ this method of cooking unless the food is completely immersed in the hot fat by means of a wire basket. This facilitates its removal with greater ease. The surface albumin is coagulated more quickly when the food is submerged, thus preventing it from soaking up too great an amount of fat.
Deep-fat cooking requires close watching and for this reason most cooks use a skillet. Unless the skillet is very hot and the meat is turned frequently, the meat juices are lost both by evaporation and by the meat adhering to the pan.
In cooking in deep fat, if not left too long and if the fat is at the right heat, the meat fibers do not soak up the fat, because the water in the tissues is so rapidly turned to steam that the fat cannot enter; the interior thus cooks in its own juices as in roasting or broiling. Fish or chops fried in deep fat are palatable and of high flavor. Boiled fish, however, if the water is well salted to prevent too great softening, is better for invalids, as it is more easily digested.
Fish fried whole in deep fat may have the skin removed after frying. The fish fibers are thus not brought into contact with the fat. Special utensils for frying fish in this way may now be obtained.
Fats are readily absorbed in their natural condition, but, if changed by extreme heat, they are irritants.