PRACTICAL SUGGESTIONS FOR USING A FIRELESS COOKER

While success in using a cooker is reasonably sure if directions are clear and detailed, and can be followed exactly, yet it is well to understand, in a general way, the conditions of success in order that a deviation from directions, if such should ever be found necessary, will not mean failure.

As the cooking depends upon the retention of heat, it stands to reason that there must be heat to retain. A pint of food does not contain as much heat as a quart, even though both be of the same temperature to begin with. This can be demonstrated by setting a pint and a quart of boiling water side by side. The pint will lose its small amount of heat and grow cold much sooner than the quart, with its larger amount. After an equal time eight quarts of food in the cooker have been found to register 15 degrees Fahrenheit higher than one and one-half quarts, other conditions being the same. This explains the failures of some beginners which are due to the fact that such a small quantity of food was taken that there was not sufficient heat to begin with. Obviously this danger is less with foods requiring only a slight cooking, since, even with small quantities, some time elapses before the food grows too cold to cook at all.

The total quantity of food is, therefore, seen to be an important factor in success. The larger the amount of food, the higher the temperature will be at the end of a given length of time. Where the amount is very large, as in the case of hotel and institution cookery, this gain is so great that the time required for cooking is materially reduced.

The proportion between the amount of food and the size of the utensil in which it is cooked is equally important. Experiments have shown that one and one-half quarts of water, in a pail just large enough to hold it, will register 15 degrees Fahrenheit more than the same measure of water in a nine-quart pail at the end of an hour; while at the end of twelve hours there is 28 degrees of difference. It is thus seen that a well-filled kettle is more likely to cook successfully than one partially filled. When it is impossible to cook in a smaller pail, and thus avoid vacant space in the kettle, the difficulty may, to some extent, be offset by using a pan for the food with sloping sides and broad rim, such as a “pudding pan,” which may be set into the cooker-pail and, by resting upon its rim, will be suspended in it. This arrangement admits of filling the lower part of the pail with boiling water or with boiling food, in case a second kind of food is to be cooked for the same length of time.

Space between the pail and packing material is also likely to be disastrous, so that it is not advisable to try to use a small pail in a “nest” made for a large one without the “space adjuster” described on [page 22]. Even the space which results after a short use of a newly packed box will be sufficient for the escape of some heat and should always be filled in.

Place the cooker near the stove, since it is important to transfer the food very quickly from one to the other. The cooker should be open, the cushion removed and everything in readiness before the food is taken from the fire; then, before it has time to stop boiling, it should be in place in the box. Loss of time at this juncture owing to uncertain movements is a fruitful source of failure among beginners.

Keep the box tightly closed from the moment the food is put into it until it is entirely done, as if for any reason the box is opened before the appointed time, the contents must be reheated to boiling point before being replaced.

The time for cooking foods on the stove, previous to putting them into the cooker, is usually very short. Food in large, solid masses, as ham, pot roasts, moulds of bread, etc., must be boiled until thoroughly heated to the centre, obviously requiring longer boiling the larger and denser the pieces are. Food that is broken and less compact will be readily penetrated by heat and will be boiling hot nearly or quite as soon as the surrounding water. Such foods need only a moment’s brisk boiling before being put into the cooker. Cereals, although in fine particles, easily settle into a dense, impenetrable mass during the long period of undisturbed cooking, unless boiled until they are slightly thickened.