Selection and preparation of food

Place 2 tbsp of ground coffee in the pot. If desired, \ tsp of beaten egg may be added. Pour over this 1 c of cold water. Bring slowly to the boiling point. Let boil up once. Clear the spout by pouring 1 tbsp of cold water through it. Let stand for about 5 minutes where it will keep hot while settling. (b) Made with boiling water. Repeat the process in (a), except that the water added should be boiling. (c) Filtered. Place 2 tbsp of finely ground coffee into a muslin sack or strainer in the coffee pot. Pour 1 c boiling water slowly over the coffee. When this has filtered through, heat and pour over again. The coffee pot must be kept hot, but filtered coffee should not be boiled. If a percolator is used the process should be watched, and when the coffee is strong enough the flame should be so regulated that the coffee is kept hot but not boiling. (d) Prepare coffee by any one of the methods given above, but let boil 10 minutes. Compare results and explain differences. 1 6 Preparation of Food Experiment 21. Tea. Arrange so that the following samples shall be ready at the same time : (a) Green tea. In each of three hot teapots place 1 tsp of green tea, adding 1 c freshly boiled water. Steep (1)5 minutes. Steep (2) 20 minutes. Boil (3) 3 minutes. (&) Black tea. Repeat (a), using black tea. (c) Place 1 J tsp of green and black tea each in separate strainers. Pour 1 c boiling water through. Observe differences in results. Compare all these samples as to color, flavor, and strength. To a small portion of each in a test tube add a few drops of a 10 per cent solution of lead acetate. What is the precipitate ? Is the amount of the precipitate the same in each case? What conclusions may be drawn from the precipitate in regard to the composition of the tea and the method of making ? Which tea and which method of preparation are to be preferred for table use? For afternoon tea? For iced tea? Laboratory Manual 17 PROTEIN FOODS MILK References: Sherman. Food Products. Sherman. Chemistry of Food and Nutrition. Rosenau. The Milk Question. Van Slyke. Modern Method of Testing Milk and Milk Products. Buchanan. Household Bacteriology. Farmers' Bulletin 348. Bacteria in Milk. Farmers' Bulletin 363. Use of Milk as Food. Farmers' Bulletin 413. Care of Milk and Its Use in the Home. Farmers' Bulletin 487. Cheese and Its Economical Use in the Diet. Bureau of Animal Industry, Circular 197. Directions for the Home Pasteurization of Milk. Bureau of Animal Industry, Circular 171. Fermented Milks. Experiment 22. Specific Gravity of Milk. Weigh 1 c of water carefully to tenths of a gram. Using the same cup for measuring, weigh also 1 c of milk. Compute the specific gravity of the milk, taking the weight of the water as unity. What conditions may affect the specific gravity of milk? 18 Preparation of Food Experiment 23. Specific Gravity of Cream. Repeat Experiment 22. What conditions may affect the specific gravity of Experiment 24. Separation of Fat. Cream. Fill a 100 c.c. graduated cylinder with fresh milk. Let stand 12 hours. Compute the percentage of cream in the sample. Observe the relative amount of cream in a bottle of milk as purchased. What is the principle upon which a cream separator operates ? Experiment 25. Separation of Fat. Butter.