FoodNet

Experimental cookery

1932

Page 60

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
To 1 cup of water add a scant Y\ cup of salt. Heat to the boiling point. Note the temperature. Continue boiling. Does the temperature change? Con- tinue boiling until the temperature remains constant. What other change occurs? What Is the effect on the boiling point when salt is added to water? Results and conclusions. Experiment 4. To determine the boiling temperature of sugar sirups corresponding to the "cold-water tests" used in candy making. A. Sucrose sirup. Dissolve 1 cup of sucrose (granulated sugar) In Yz cup of water. (The proportion of sugar and water used may need to be Increased. The quantity of sirup should be sufficient to cover the thermometer stem to a depth of Yz Inch above the bulb. The amount of sugar needed depends upon the size of the pan and the length of the thermometer bulb.) Bring the solution to boiling. Note rise in temperature with constant boiling. Explain. Why can a higher temperature be obtained with the sugar solution than with the salt solution? Cook the sirup In sauce pans of the same size and shape. At the tempera- tures given below remove portions of the sirup. Remove the pan from the stove when making each test. Drop a tablespoon of the sirup in cold water. Note the consistency. Is it easily molded? Does It ring when hit against the side of the container? When do threads or hairs begin to form when a portion of the sirup Is allowed to flow from a spoon? How do the character and length of the threads vary at different temperatures? Keep the series of tests on your work tray for comparison with the following experiments and with your neighbors' results. Note the texture at room temperature. Is it soft, firm, or brittle? Put a portion In your mouth. Does It dissolve rapidly on the tongue? To what stage in candy cookery does each of the temperatures given correspond? LABORATORY OUTLINE 73 Compare with results given in candy and in cook books. Tabulate your results. Tempera- Texture ture Threads Stage of cookery Used for °c. °F. In Room On the water temperature tongue Ill 113 118 122 132 145 170 B. Sucrose and corn sirup. Dissolve ^ cup (100 grams) of sucrose and Yz cup (162 grams) of com- mercial corn sirup in 1/3 cup of water. Repeat directions under 4A. What is the effect on the stage of cookery or hardness when one-half sucrose and one- half corn sirup are used? Compare your results with those of Miss Daniels in J. Home Econ. 6: 457 and 482 (1914). Tempera- ture Texture Threads Stage of cookery Used °C. °F. In water Room temperature On the tongue for Ill 113 118 122 132 145 170 C. Sucrose and crystalline dextrose. Dissolve Yz cup (100 grams) of sucrose and Yi cup of crystalline dextrose (80 grams) in Yi cup of water. Repeat directions under 4A. How does the hardness of the sirups obtained under 4A, 4B, and 4C compare for any given definite temperature, for example, 118°C.? 74 SUGAR COOKERY Tempera- ture Texture Threads Stage of cookery Used for °C. °F. In Room On the water temperature tongue Ill 113 118 122 132 145 170 D. Sucrose and dextrin. Dissolve Yz cup (100 grams) of sucrose and water. Repeat directions under 4A. cup of dextrin in Yi cup of Tempera- ture Texture Threads Stage of cookery Used for °C. °F. In Room On the water temperature tongue Ill 113 118 122 132 145 170