CREAM SEPARATION 77 



LABORATORY PROBLEMS 



XI. To Determine the Pek Cent of Fat in Cream 



a. Carefully weigh 18 grams of cream into a 30 

 per cent cream test bottle. 



b. Add about the normal amount of sulphuric acid 

 (17.5 c.c). 



c. Test as in the case of whole milk ; that is, whirl 

 three times and fill twice. 



d. Place in a water bath having a temperature of 

 120 to 140 degrees. 



e. Before reading add a few drops of white min- 

 eral oil or colored denatured alcohol. Care must be 

 exercised to prevent the oil from mixing with the fat 

 column. This can best be accomplished by allowing 

 the oil to run slowly down the side of the neck. 



LABORATORY PROBLEMS 



XII. To Determine the Richness of Cream by Use of 50 Per 

 Cent 9-Gram Bottu: 



In many states the 50 per cent 9-gram bottle is 

 used instead of the 18-gram 30 per cent bottle. This 

 means that 9 grams are used as a charge. 



a. Weigh out 9 grams of cream into bottle. 



b. Add about 9 c.c. of clear water. Mix. 



c. Add normal amount of sulphuric acid (17.5 c.c). 



d. Test as in the case of milk. ' Place in water bath 

 and then read, using white mineral oil or colored 

 denatured alcohol to level the meniscus. 



e. In case a 9-gram bottle is used the reading is 

 direct, as the bottle is calibrated to read direct. In 

 case an 18-gram bottle is used, then the reading must 

 be multiplied by 2, because 9 grams is only half a 

 charge. 



