114 DAIBY CHEMISTRY 



enables the renovated butter to be easily detected. 

 Some of the states have laws requiring that butter 

 treated in this way shall be stamped or labeled 

 "Renovated Butter." 



106. Adulteration of Cheese. — Cheese is adulter- 

 ated (1) by removing a portion of the fat from the 

 milk and then manufacturing the skimmed or par- 

 tially skimmed milk into cheese ; (2) by completely 

 removing the milk fats and substituting other and 

 cheaper fats, thus producing so-called " filled cheese." 

 The foreign fats are incorporated with the skim 

 milk while in the vats and then the process of 

 cheese making is completed, with slight modifica- 

 tions, as outlined in the chapter on Cheese Making. 

 The addition of foreign fats to the cheese can be 

 readily detected by chemical analysis, as cotton-seed 

 oil and other fats have different chemical and physi- 

 cal properties from butter fats. For the determina- 

 tion of the per cent of fat in cheese by the Babcock 

 test, see section 92. Cheese with 28 per cent or 

 less of fat can be considered as made from partially 

 skimmed milk, and the lower the per cent of fat in 

 the cheese, the more extensively has the skimming 

 been practiced. 



107. Adulteration of Milk. — The way in which 

 the lactometer and Babcock test may be used for 

 detecting skimming and watering is described in 

 Chapter IV. In addition to skimming and water- 

 ing, milk is sometimes adulterated by the addition 

 of preservatives. The materials employed for the 



