Although the making of stock or soup is a simple process, it must necessarily be a rather long one. The reason for this is that all flavor cannot be drawn from the soup materials unless they are subjected to long, slow cooking at a temperature lower than the boiling point. With this point definitely understood, the actual work of soup making may be taken up.

COOKING MEAT FOR SOUP.--When clear stock is to be made from fresh meat, the required quantity of meat should be cut into small pieces rather than large ones, so as to expose as much of the surface as possible from which the flavor of the meat can be drawn. A little more flavor is obtained and a brown color developed if a small part, perhaps a fourth, of the pieces of meat are first browned in the frying pan. The pieces thus browned, together with the pieces of fresh meat, are put into a kettle and a quart of cold water for each pound of meat is then added.

The reason for using cold rather than hot water will be evident when the action of water on raw meat is understood. The fiber of meat is composed of innumerable thread-like tubes containing the flavor that is to be drawn out into the water in order to make the stock appetizing. When the meat is cut, these tiny tubes are laid open. Putting the meat thus prepared into cold water and allowing it to heat gradually tend to extract the contents of the tubes. This material is known as extractives, and it contains in its composition stimulating substances. On the other hand, plunging the meat into hot water and subjecting it quickly to a high temperature will coagulate the protein in the tissue and prevent the extractives from leaving the tubes.

To obtain the most flavor from meat that is properly prepared, it should be put over a slow fire and allowed to come gradually to the boiling point. As the water approaches the boiling point, a scum consisting of coagulated albumin, blood, and foreign material will begin to rise to the top, but this should be skimmed off at once and the process of skimming continued until no scum remains. When the water begins to boil rapidly, either the fire should be lowered or the kettle should be removed to a cooler part of the stove so that the water will bubble only enough for a very slight motion to be observed. Throughout the cooking, the meat should not be allowed to boil violently nor to cease bubbling entirely.

The meat should be allowed to cook for at least 4 hours, but longer if possible. If, during this long cooking, too much water evaporates, more should be added to dilute the stock. The salt that is required for seasoning may be added just a few minutes before the stock is removed from the kettle. However, it is better to add the salt, together with the other seasonings, after the stock has been drawn off, for salt, like heat, has a tendency to harden the tissues of meat and to prevent the flavor from being readily extracted.

Although, as has been explained, flavor is drawn from the fibers of meat by boiling it slowly for a long time, the cooking of meat for soup does not extract the nourishment from it to any extent. In reality, the meat itself largely retains its original nutritive value after it has been cooked for soup, although a small quantity of protein is drawn out and much of the fat is removed. This meat should never be wasted; rather, it should be used carefully with materials that will take the place of the flavor that has been cooked from it.