FoodNet

Food study

1917

Page 47 · 2 recipe records on this page

Presented as published in 1917. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
1. Prepare a small bowl of: a. cracked ice. 6. mixture of one part of salt to one part of ice. c. mixture of one part of salt to seven parts of ice. d. mixture of one part of salt to ten parts of ice. Insert a thermometer in each bowl as soon as the ice and salt are mixed and find the lowest temperature obtainable in each case, also the length of time neces- sary to obtain this temperature. FREEZING 91 2. Effect of different freezing mixtures. Prepare a syrup, using two tablespoons of sugar to one-half cup of water. Pour into four test tubes. Prepare bowls as in (1) and insert one of the test tubes in each. Compare the time required to freeze, and the textures of the frozen syrups. Which freezing mixture will you use to freeze an ice or a sherbet ? 3. Insert in a freezing mixture of one part of salt to seven parts of ice test tubes containing : a. a tablespoon of water. b. a tablespoon of water and a saltspoon of ground spice. c. a tablespoon of syrup (one part sugar to four parts of water). d. a tablespoon of syrup (one part sugar to one part of water). e. a tablespoon of stiffly beaten white of egg. Notice the time necessary to freeze and the texture of each. Take the temperature of each when frozen. What is the effect of suspended and dissolved sub- stances on the freezing point of water ? B. PREPARE LEMON ICE. Boil two tablespoons of sugar with half a cup of water to make a syrup. Add one tablespoon of lemon juice. Cool, pour into a tin measuring cup or similar container, cover, and surround with ice and salt. (What proportion will you use ?) Stir while freezing. C. Class Work. PREPARE LEMON SHERBET. Prepare a syrup, using the same proportions as in (B) but make enough to serve the whole class. Freeze in a regular freezer. 1. Use two teaspoons of gelatineLemon Sherbet for every quart of liquid. Soak the gelatine in a little cold water, while 92 FOOD STUDY the syrup is cooking. Then pour the hot syrup over it. Add lemon in the same proportion given in (B) and strain. Grated lemon peel may be added. Or: 2. When syrup is cool, mix in stiffly beaten white of egg, using one-half to one egg white for each cup of liquid. Add lemon as before. FREEZING MIXTURES Without a knowledge of physics it is rather difficult to understand how ice and salt act as a freezing mixture. In order to understand it at all we must know some prelimi- nary facts. In the first place, the subject of energy must be considered. Cold is not a thing in itself, but merely the absence of heat. Heat, light, electricity, magnetism, and motion are all forms of energy and can be transformed one into another. Electricity in our lamps, for example, is changed into light and also gives off heat. In an electric flat-iron, heat is produced without any light at all. The heat of the fuel is, in a locomotive, turned into the motion which carries the train along. It is well-known, too, that some substances, as a piece of hard rubber such as is found in a fountain pen, can easily be electrified on a cold day by rubbing briskly on a woollen surface and that they will then attract bits of paper. These are all cases where one form of energy is turned into another ; and it is a law in physics that no energy is ever destroyed, but continues to exist.