90 Testing Milk and Its Products. 



either reach entirely through or only half way through 

 the cheese. 



"For inspection purposes the rind may be rejected, but 

 for investigations, where the absolute quantity of fat in 

 the cheese is required, the rind should be included in the 

 sample. It is well, when admissible, to take two or three 

 plugs on different sides of the cheese and after splitting 

 them lengthwise with a sharp knife, take portions of each 

 for the test." 



103. When a satisfactory sample of the cheese has been 

 obtained, about 5 grams are weighed into a milk test 

 bottle, or a larger quantity may be used with a cream 

 test bottle. The test bottle is first weighed empty, and 

 again after the pieces of cheese have been added. About 

 15 cc. of warm water is added to the cheese in the test 

 bottle, and this is shaken occasionally until the cheese 

 softens and forms a creamy emulsion with the water. 

 A few cc. of acid will aid in this mixing and disintegra- 

 tion. When all lumps of cheese have disappeared in 

 the liquid, the full amount of acid is added, and the test 

 completed in the ordinary manner. 



The per cent, of fat in the cheese is obtained by multi- 

 plying the reading of the fat column by 18 and dividing 

 the product by the weight of cheese added to the test 

 bottle. The weighing of the cheese and the reading of 

 the fat must be done with great care, since any error 

 introduced is more than trebled in calculating the per 

 cent, of fat in the cheese. 



104. Condensed milk. The per cent, of fat in un- 

 sweetened condensed milk can be obtained by weighing 

 8 grams into a test bottle and proceeding in exactly the 



