A DAIRY LABORATORY GUIDE 23 



THE C. U. BUTTER MOISTURE TEST 



When butter is heated over a flame, the casein 

 forms a snow-white blanket over the surface of the 

 butter. By a comparison with the chemical method 

 it has been found that when the butter loses its 

 snow-white color and turns a dirty brown color the 

 sample has given up its moisture. When this 

 brown color has appeared it is time to remove the 

 sample from the flame. Heating butter in a direct 

 flame is liable to volatilize some of the butter, even 

 before all of the water has been given off. In order 

 to do away with this danger a sheet of asbestos is 

 placed between the flame and the container oi the 

 sample. The asbestos so tempers the flame that 

 while a high heat is produced, the danger of sud- 

 denly volatilizing the butter is largely done away 

 with. 



The scales used are made especially for use in 

 butter-moisture work. They are so constructed 

 that after the moisture is driven off, each notch 

 the large weight is reversed equals i per cent of 

 moisture driven off, and each notch that the small 

 weight is reversed equals .i per cent of moisture 

 driven oflF. Always allow the sample to cool be- 

 fore weighing. While the sample is cooling it is 

 well to cover it with something (a sheet of paper 

 will do), so that the sample will not take water 

 from the air. 



