51. Other Devices Belonging to Cookers. In most commercial cookers there are wire devices to raise the dishes of food from the stone (Fig. 23). This prevents scorching and boiling over when the stones are heated very hot. These devices are also used to hold a hot stone above the food to make a brown crust on it. Some cookers are furnished with valves, permitting the escape of steam when it becomes too abundant. The pressure of the steam automatically opens the valve. This device insures the cooking of certain vegetables, cereals or doughs without their becoming too soggy to be palatable (A, Fig. 23).
52. Directions for Using the Cooker. Put the stones on to heat. Prepare the food as for cooking in any other way. Then heat it, either in the oven or on top of the stove. It is preferable to heat the food in the same vessel in which it is to be cooked in the fireless cooker. Transferring food to a cold vessel entails a loss of heat, since the first vessel is already heated.
Fig. 23. Devices for fireless cooker.
When the stones and food are hot, place the stone in the bottom of the cooker. Put in any asbestos mats or other devices which are needed to protect the food. The stone should be hot enough to respond to the test for flat irons. It should make the snappy noise of a good hot iron when the finger is moistened and touched to it. Place the food in the cooker. Place another stone above the utensil if it is desirable to have the food brown on top. Close the fireless cooker, and let it stand until ready for use.
Fig. 24. Gas cookers.
53. Time of Cooking Food. Six hours or over night should be allowed for the cooking of cereals. Stews should be given two to three hours' time for cooking.
Large roasts and hams require five to six hours. It is sometimes necessary, when they are large, to remove them and heat the food and the stones on the stove once during the process of cooking. Dumplings and angel cakes cook well in a fireless cooker. So do all dried peas and beans.