FoodNet

Domestic science (Johnson, for schools and homes)

1911

Page 39

Presented as published in 1911. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
A sufficiently high degree of heat will destroy all forms of life; hence, heat is usually employed to destroy the bac- teria in food before it is canned. The food to be canned should be cut in pieces of suitable size, placed in water and heated to a brisk boil. It must be remembered that if a single bacterium is left alive in the food after the boiling, the whole process is useless, and the canned goods will spoiL Some kinds of bacteria are not so easily destroyed as others, hence it is best to boil all foods to be canned, as thoroughly as their nature will allow. Green corn is very difficult to can, 86 DOMESTIC SCIENCE requiring a very high degree of heat; this is true of peas, beans, and tomatoes, also. Common liquids, boiled in open vessels, cannot be heated above 212 degrees, Fahr; but can be raised to a much higher temperature in a closed vessel, tight enough to prevent the escape of the steam, and strong enough to prevent Fig. 22— Spring-top jar. Fig. 23~Position of spring during sterilizing. Fig. 24— Position of spring after sterilizing. COOKING 87 bursting by the steam. A temperature of 212 degrees does not destroy all kinds of spores, but, if the time of boiling be prolonged at 212 degrees, the eflPect will be the same as that of a higher temperature. It is better to place the food in cold water, and then bring it to boiling point. Review lesson No. 35, seventh year. Hermetical Sealing, to prevent the access of air to the food, is easy and eflFective. The food should be poured into thoroughly sterilized jars while it is hot, and the jars should be sealed immediately. Cans may be corked with cotton which has been previously sterilized by the heat of an oven, keeping the food from bacteria; but this method does not wholly exclude moulds. Most forms of fruit are canned with little difficulty, re- quiring only moderate boiling and careful sealing. The spring-top glass jar and the screw-top glass jar are best adapted to the purpose of hermetical sealing. A wide- mouthed jar should be selected, for convenience. Lesson 35. Planning a Simple Dinner: This should be made a lesson in economy, as well as a lesson in cooking. Each pupil should present a menu for the dinner. The one selected should be copied by each pupil. Lesson 36. Cooking and Serving the menu previously selected. Serving invited guests. APPENDIX. PART IV. For the Use of Classes Having More than One Lesson per Week; for Home Use, and For General Reference. APPENDIX. A. The foods eaten, nourish the body to its growth, and repair all tissue waste produced by both physical and mental action. The body, then, must contain, in its healthful state, all the chemical elements found in these foods. The principal of which are as follows: FroTEIDS. Carbon, Oxygen, Chemical Elements. Fats. Carbo- hydrates. 54. 22. Nitrogen, 16. Hydrogen, 7. Sulphur, 1^ I 100. Carbon, 79. \ Hydrogen, 11. Oxygen, 10. 100. Hydrogen, 67. Oxygen, 33. Carbon,(variable). lOOe Fig. 25. In the Carbo-hydrates, the hydrogen and oxygen unite to form water. This union exhausts the normal power of 89 90 DOMESTIC SCIENCE eacK of these elements, so that the Carbon, alone, is left to do its normal work; that of producing heat and energy.