THE TESTING OF MILK AND CREAM 119 



column is caused by too warm milk and acid, or too much or 

 too strong acid. 



Such tests should be rejected, as the readings of the same are 

 prone to be inaccurate. 



The appearance of foam on the surface of the fat column is 

 caused by the use of hard water. The carbonates, when acted 

 on by the sulfuric acid, break down, liberating carbon dioxide 

 gas which, rising through the fat column, gathers on its surface 

 in the form of air bubbles. Where soft water, distilled water, 

 or rain water is not available, the water may be softened by 

 boiling it or by the addition to it of a few drops of sulfuric acid 

 before use. 



cream testing (Hunziker) 



Sampling the cream 



One of the most common causes of incorrect cream tests lies 

 in the inaccuracy of the cream sample. The difficulty of secur- 

 ing accurate cream samples is greatly augmented by the fact 

 that the cream, at the time of sampling, is often in no condition 

 to be sampled correctly. 

 Care of the cream on the farm. \ 



In order to facilitate accurate sampling by the cream hauler, 

 shipping station agent, or creamery, the cream should receive 

 the proper care on the farm. The separator should be 

 thoroughly cleaned after each separation and the cream screw 

 or skim-milk screw so set as, to discharge cream containing 

 about 35 to 45 per cent fat. After separation the cream should 

 be cooled and kept cool. This is best done by setting the cans 

 containing it into a trough or tank of cold water. The cream 

 cans should remain in the cold water until they leave the 

 farm. The cream should be stirred occasionally to prevent 

 excessive separation of the fat and the drying of the cream on 

 the surface, 



