154 CREAMERY BUTTER MAKING 



possible. Wherever permissible open conductors should 

 be used in preference to pipes. The cream should be run 

 through an open conductor from the ripener to the churn. 

 When the air pump is used the end into which the cream 

 is pumped should be closed about two feet to prevent the 

 cream from spattering out. 



Particular attention is called to the combined heater and 

 milk pump. Where a heater like the hLeid pasteurizer is 

 used no pump is required to elevate or force the milk into 

 the separators. Such a machine will elevate the milk to 

 practically any height desired. It is easily cleaned, seldom 

 out of repair, heats the milk evenly and gradually, and 

 requires no over-flow for milk as is the case with milk 

 pumps. It is true, however, that the original cost of such 

 a machine is somewhat greater than that of a separate 

 heater and pump, but the ease in cleaning and the saving 

 in repairs, floor space, and pipes more than compensate 

 for this extra cost. 



In addition to serving as an ordinary heater and pump, 

 such a pasteurizer may serve another and most impor- 

 tant purpose, namely, that of a milk pasteurizer. Indeed, 

 it is to be recommended that the milk be heated to the 

 pasteurizing temperature before entering the separators 

 whenever weed}- or nearly frozen milk is received at the 

 creamery. Our experience has shown that running milk 

 through the separator at temperatures between i6o" and 

 i8o" F has three distinct advantages: 



a. Increases the efficiency of skimming. 



b. Eliminates weedy flavors 



c. Destroys bacteria. 



a. Efficiency of Skimming. During the past two 

 winters careful tests were made at our dairv school to 



