Page:Foods and their adulteration; origin, manufacture, and composition of food products; description of common adulterations, food standards, and national food laws and regulations (IA foodstheiradulte02wile).pdf/112

 perfectly safe at low pressure and supplied with a safety valve so as to allow steam to escape if the pressure runs too high. Several hours of digestion are necessary for the preparation of stock, and if an ordinary vessel is used care must be exercised that the liquid does not evaporate so as to make the mass dry. Stirring from time to time assists the solution of the soluble substances. After the extraction is complete the liquid contents are poured off and the solid material pressed gently to separate the liquid held in solution. The mass is then put in a cool place and allowed to stand until thoroughly cooled and all the fat particles are collected at the top. The fat is then removed and the resulting liquid strained to remove any solid particles. The clear solution thus obtained is set aside and used as stock in the preparation of the various forms of soups. When properly flavored and used by itself it produces the soup known as consommé.

The soup stock made in this way usually contains not less than 95 percent of water and not more than 5 percent of nutritive matter. Many of the clear soups prepared in this way contain very much less nutritive matter, sometimes as low as one percent. It is evident, therefore, that the soup stock is valuable as a condiment and flavoring and not as a food.

The number of soups which can be made from soup stock is practically unlimited. They are formed by the admixture, chiefly of vegetables cut into small pieces, of starchy materials, mashed peas or beans, particles of potato, fragments of parched bread, and in fact almost any nutritive and palatable substance which the cook may wish to employ.

A soup made from a stock of the above description with pea flour was found to have the following composition:

Water,                              88.26 percent Protein,                             3.38    " Fat,                                   .93    " Ash,                                 1.13    " Starch and other carbohydrates,       6.30    "

A soup made with potatoes from stock of the above description was found to have the following composition:

Water,                              90.96 percent Protein,                             1.37    " Fat,                                  1.53    " Ash,                                  .99    " Starch and other carbohydrates,       5.13    "

The French make soups which are very well known and highly valued by cutting vegetables, such as carrots, beets, radishes and other vegetable substances, into small pieces and adding them to the soup stock.

Oyster Soup.—A soup made of milk, cream, flour, condiments, oysters and the liquid of oysters is very largely eaten in the United States. The dif-