Put the white of egg into the test-tube. Insert the thermometer. Hold the test-tube in the pan of cold water to the depth of the egg white. Gradually heat the water and observe the temperature at which the first change in the egg albumen takes place. Notice also the temperature of the water at this point. Continue the experiment until the water in the outer vessel has boiled ten or twenty minutes, noting the temperatures at which the various changes occur.
Experiment B: To show the temperatures obtained in the proper cooking of eggs.
Materials:
- Fireless cooker
- Eggs
- Water
- Thermometer
Cook eggs as directed for soft-cooked eggs on [page 190], observing the temperature of the water after the eggs are added to it, and when they are removed from the cooker; also the condition, flavour, etc., of the eggs.
Cereal Proteids
Professor Harcourt, in his bulletin, “Breakfast Foods,” published by the Ontario Department of Agriculture, pp. 20 and 29, says that long cooking of cereals renders the protein more digestible. The cooking which he describes was carried on in a double boiler, and, therefore, below boiling temperature, and in this respect is similar to fireless cookery. He says that while short cooking, which was done at boiling temperature, seemed to make cereal proteids less digestible, the long cooking at below boiling temperature, which followed, somewhat changed them and made them more digestible.
While little study appears to have been made of the digestibility of cereal proteids when cooked for a long time at a low temperature, it is probably fair, in the absence of further definite information, to assume that, like animal proteids, it is better to cook them at a low temperature such as that of the fireless cooker, than at the temperature of boiling water or higher.
Meat Proteids
In the bulletin entitled “A Precise Method of Roasting Meat,” by Elizabeth A. Sprague and H. S. Grindley, published by the University of Illinois, a study is made of the temperatures at which the changes take place from raw meat to “rare”; from “rare” to “medium rare,” and from this to “well done” meat. The authors found that if the centre of the meat is between 130 degrees and 148 degrees Fahrenheit (55 degrees and 65 degrees Centigrade), it is rare; if it is between 148 degrees and 158 degrees Fahrenheit (65 degrees and 70 degrees Centigrade), it is medium rare; and if it is between 158 degrees and 176 degrees Fahrenheit (70 degrees and 80 degrees Centigrade), it is well done. They found no advantage in cooking meat in a very hot oven (385 degrees Fahrenheit, or 195 degrees Centigrade), but rather a difficulty to keep it from burning; that in an oven which was about 350 degrees Fahrenheit (175 degrees Centigrade), the meat cooked better; and that in an Aladdin oven which kept the meat at about 212 degrees Fahrenheit (100 degrees Centigrade), it cooked best of all; that is, it was of more uniform character all through, more juicy, and more high flavoured. This seems to point to an advantage in fireless cookery for meats, and practical experience bears it out.