200 DAIRY FARMING 



once and store in ice water or in an ice box. Adjust the tempera- 

 ture of the other sample to between 70 and 80 and leave in a warm 

 room. How long before each sours ? 



"CREAM SEPARATORS 



30. Separation of Cream. The students should obtain samples 

 of skim-milk from as many sources as possible, some from cream 

 separators, and others from places where the cream is separated by 

 gravity. Make the Babcock test, preferably using a special skim- 

 milk test bottle. What was the loss of butter-fat by each method 

 of separation ? 



BUTTER AND CHEESE 



31. Study of a Factory. Visit a butter, cheese, or condensed 

 milk factory, and learn as much as possible of the methods of manu- 

 facture, also of the methods of buying, selling, and management. 



32. Judging Butter. If the assistance of a creamery man or 

 other competent judge of butter can be had, the class may gather 

 a number of butter samples representing the local supply, and judge 

 them with his assistance. 



CHEESE 



33. Making Curd. Dissolve a rennet tablet according to the 

 directions of the manufacturer, add it to milk and observe the effect. 

 Compare the curd formed with that from sour milk in taste and con- 

 dition. Curd made in this way is used in cheese making. 



34. Fat in Cheese. Weigh out 5 grams of cheese, cut it into 

 small pieces, and put in a milk test bottle. Add 10 cc. of warm 

 water and acid as in testing milk. After the cheese is dissolved, 

 complete the test as for milk. 



Since the test bottle is graduated for 18 grams, the percentage of 

 fat for the cheese must be calculated for that amount by dividing 

 the fat reading by the weight of cheese taken in grams and multi- 

 plying the result by 18. 



COLLATERAL READING 



The Production of Clean Milk, U. S. Dept. Agr., Farmers' Bulle- 

 tin 602. 



Bacteria in Milk, U. S. Dept. Agr., Farmers' Bulletin 490. 



The Care of Milk and Its Use in the Home, U. S. Dept. Agr., 

 Farmers' Bulletin 416. 



