There is a number of methods of making soup stocks, and no two will give exactly the same results. One of the simplest and most satisfactory is that of clear stock or bouillon. By this the best flavor of the meat is obtained, for none passes off in steam, as when the meat is boiled rapidly. The second mode is in boiling the stock a great deal, to reduce it. This gives a very rich soup, with a marked difference in the flavor from that made with clear meat kept in water at the boiling point. The third way leaves a mixed stock, which will not be clear unless whites of eggs are used. In following the first methods we buy clear beef specially for the stock, and know from the beginning just how much stock there will be when the work is completed. By the second method we are not sure, because more or less than we estimate may boil away. The third stock, being made from bones and pieces of meat left from roasts, and from the trimmings of raw meats, will always be changeable in color, quantity and quality. This is, however, a very important stock, and it should always be kept on hand. No household, even where only a moderate amount of meat is used, should be without a stock-pot. It can be kept on the back of the range or stove while cooking is going on. Two or three times a week it should be put on with the trimmings and bones left from cooked and uncooked meats. This practice will give a supply of stock at all times, which will be of the greatest value in making sauces, side dishes and soups. Meat if only slightly tainted will spoil a stock; therefore great care must be taken that every particle is perfectly sweet.
Vegetables make a stock sour very quickly, so if you wish to keep a stock do not use them. Many rules advise putting vegetables into the stock-pot with the meat and water and cooking from the very beginning. When this is done they absorb the fine flavor of the meat and give the soup a rank taste. They should cook not more than an hour—the last hour—in the stock. A white stock is made with veal or poultry. The water in which a leg of mutton or fowl have been boiled makes a good stock for light soups and gravies. A soup stock must be cooled quickly or it will not keep well. In winter any kind of stock ought to keep good a week. That boiled down to a jelly will last the longest. In the warm months three days will be the average time stock will keep.