FoodNet

A textbook of domestic science for high schools

1913

Page 7

Presented as published in 1913. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
The construction of cook stoves is at present in a transition stage and drawings are not given in this text, as it is hoped soon that the construction of stoves will be materially changed. The loss of heat and the attendant waste of fuel in heating an ordinary oven is very great. It is said that only about seven per cent of the heat is utilized. Modern stoves are now being constructed with non-conducting sub- stances around the air chambers which surround the ovens so that the waste of heat is much reduced. An oven ther- mometer should be placed on every oven to substitute a scien- tific means of regulation for the old-fashioned dependence on " luck " when baking. With gas and electric stoves a ther- mostat should shut off heat when a certain temperature has been attained, the baking being then completed by the re- tained heat of the oven. Cooking is the art of preparing food for the nourishment of the human body by the aid of heat. We cook food to make it more palatable, more digestible, and to destroy any harmful bacteria which it may contain. 14 DOMESTIC SCIENCE The processes of cooking may be classed as : 1. Boiling. a. Cooking directly in water. 6. Steaming. (1) Moist, cooking in a steamer. (2) Dry, cooking in double boiler. 2. Roasting. a. Roasting in front of open fire. b. Roasting in hot oven. 3. Broiling. a. Broiling over red-hot coals or gas flame. 6. Pan-broiling in very hot pan (without fat). 4. Frying. a. Deep frying. 6. Sauteing, or frying in small amount of fat. Boiling : EXPERIMENT 11. — Put cold water in glass beaker or stewpan. Heat. With thermometer note temperature at which small bub- bles form on the bottom and sides of the beaker and rise to the surface. What are these bubbles ? Where do they break ? Note temperature at which larger bubbles rise ; and also note tempera- ture when the surface of the water is completely agitated. What are these large bubbles ? Where do they break ? What is the tem- perature of simmering water ? of boiling water ? How is the heat of the fire conveyed to the water? How is the heat conveyed through the water? Note the deposit left on the pan after the water has boiled away; what is this deposit? Give two reasons why boiled water tastes flat. Why should water be freshly boiled for tea and coffee? How can you improve the taste of water which has been boiled ? EXPERIMENT 12. — Let water boil gently. Note temperature. Let it boil rapidly. Note temperature. Does water get hotter than its boiling point in an ordinary kettle ? What becomes of the AIR AND COMBUSTION 15 excess heat? What important point in the economy of fuel in cooking does this emphasize ? EXPERIMENT 13. — A. Put equal amounts of water in two beakers of the same size. Let the water in one beaker boil gently for about five minutes ; in the other let it boil rapidly. Compare the rate of evaporation of the water in the two beakers. B. Put equal amounts of water in two vessels of equal capacity, having one vessel shallow and broad and the other deep and narrow. Boil the water in them for an equal length of time and compare the rate of evaporation in the two vessels. Does the shape of the pan used and the rapidity of boiling have any bearing on practical cookery ?