A handbook of invalid cooking

by Mary A. Boland

These experiments illustrate a very important point in the cooking of albuminous foods. They show that the proper temperature for albumen is that at which it is thoroughly coagulated, but not hardened; that is, about 160° Fahr. Most kinds of meat, milk, eggs, oysters, and fish, when cooked with reference to their albumen alone, we find are also done in the best possible manner with reference to their other constituents. For instance, if you cook an oyster thinking only of its albuminous juice, and endeavor to raise the temperature throughout all of its substance to, or near, 160° Fahr., and not higher, you will find it most satisfactory as to flavor, consistency, and digestibility. The same is true of eggs done in all ways, and of dishes made with eggs, such as custards, creams, and puddings. With the knowledge that albumen coagulates at a temperature of 52° below that of boiling water, one can appreciate the necessity of cooking eggs in water that is not boiling, and a little experiment like the above will impress it upon the mind as no amount of mere explanation can possibly do.

The cooking of eggs, whether poached, cooked in the shell, or in omelets, is of much importance, for albumen when hard, compact, and tenacious is very difficult of digestion; the gastric juice cannot easily penetrate it; sometimes it is not digested at all; while that which is properly done—cooked in such a way that it is tender and falls apart easily—is one of the most valuable forms of food for the sick.

Albumen should always be prepared in such manner as to require the least possible expenditure of force in digestion. Those who are ill cannot afford to waste energy. Whether they are forced to do so in the digestion of their food depends very much upon the person who prepares it.

Advantage is often taken, in cooking, of the fact that albumen hardens on exposure to certain degrees of heat, to form protecting layers over pieces of broiling steak, roast meats, etc. If a piece of meat is placed in cold water to cook, it is evident, since albumen is soluble in cold water, that some of it will be wasted. If the same piece is plunged into boiling water the albumen in its outer layers will be immediately hardened, and form a sheath over the whole which will keep in the juices and the very important flavors. When broth or soup is made, we put the meat (cut into small pieces to expose a large extent of surface) into cold water, because we wish to draw out as much as possible the soluble matter and the flavors. If, on the other hand, the meat is to be served boiled, and broth or soup is not the object, then this order should be reversed, and every effort made to prevent the escape of any of the ingredients of the meat into the liquid.

In broiling steak, we sacrifice a thin layer of the outside to form a protecting covering over the whole by plunging it into the hottest part of the fire, so that the albumen will become suddenly hard and firm, and plug up the pores, thus preventing the savory juices from oozing out. More will be said on this subject in the recipes for cooking these kinds of foods.

Gelatinoids. The second class of protein compounds comprises the gelatinoids, gelatin being their leading constituent. It is found in flesh, tendons, cartilage and bone; in fact, it exists in all the tissues of the body, for the walls of most of the microscopic cells of which the tissues are composed contain gelatin.

Exp. Boil a pound of lean meat freed from tendons, fat, and bone, in a pint of water for three hours; then set the liquid away to cool. Jelly resembling calf's-foot jelly will be the result. The cell-walls of the flesh have been dissolved by the long-continued action of heat and liquid. This is commonly called stock or glaze.

Exp. Put a piece of clean bone into a dilute solution of hydrochloric acid. In two or three days the acid will have acted upon the earthy matters in the bone to remove them, and gelatin will remain. The average amount in bone is about thirty per cent.

Calves' feet were formerly used for jelly because of the excess of gelatin which they contain. They were cooked in water for a long time and the liquid reduced by further boiling; it was then clarified, flavored, and cooled; the result was a transparent, trembling jelly. The prepared gelatin of commerce, or gelatine, has now largely displaced this, for it is much more convenient to use, and less expensive.