332 THE BOOK OF CHEESE 



agricultural experiment stations examine all glassware 

 and mark it to make certain that it conforms to the re- 

 quirements of the state law. In New York, glassware 

 found to be correct is branded " S. B.," which means 

 State Brand. In some states a person must have a 

 license to test milk or cream, when it is paid for on the 

 fat test. Such a person must pass an examination to 

 show that he understands the test before a license, will be 

 granted. The license may be revoked if the work is not 

 honestly performed. 



313. Testing whey for fat. Because of the small 

 amount of fat in whey, it is difficult to obtain a repre- 

 sentative sample. The best way, if the entire amount 

 cannot be placed in a vat and stirred, is to catch a little 

 of the whey at intervals as it is being drawn from the vat. 

 The sample to be tested is measured with the pipette 

 the same as the milk and placed in the skimmed-milk test 

 bottle. The same acid is used to test whey as to test 

 milk but because there are not so many solids to destroy, 

 not so much is used. If as much acid is used with whey 

 as with milk, it will burn the fat and so interfere with 

 the reading of the test. Just enough acid is added to 

 destroy the milk substances except the fat, or enough to 

 turn the contents of the test bottle dark brown. This 

 usually requires filling the acid measure one-quarter of 

 an inch under the graduation. The remainder of the 

 test is the same as for whole milk. 



314. Testing cheese for fat. The sample of cheese 

 to test for fat is obtained by removing the sample with a 

 cheese-trier. This sample is called a " plug." Different 

 plugs from the same cheese will test various percentages 

 of fat so that it is difficult to secure a representative 

 sample. The usual practice is to take three plugs, one 



