628 BOARD OF AGRICULTURE. 



of milk before pasteurization had tlie following average germs per c.c. 

 (cubic centimetre) after beating to the temperatures given in a continuous 

 pasteurizer: 



Temperature. Av. No. gtrmiper c. c. 



140 degrees F 631,046 



100 degrees F 12,848 



185 degrees F 81 



195 degrees F 40 



Not all the germs are killed by heating, but most of them are de- 

 stroyed at 185 degrees. 



2. Stable and feed flavors are eliminated from milk by the heating. 

 No matter how careful we may be there is more or less taint from the 

 stable in winter. As feed flavors are due to volatile oils, these have an 

 opportunity to pass off in the heating process. Pasteurization is not to 

 be considered an excuse for careless feeding of cows or handling of milk, 

 but it is an aid to the butter maker, whether in the creamery or in the 

 farm dairj', who does not have perfect milk or cream to make into butter. 



3. It places the control of the cream ripening in the hands of the 

 buttermaker. This is tho most difficult part of buttermaking. If the milk 

 or cream be delivered soui- or off in flavor, it is not possible to make tine 

 biitter out of it. First-class butter can not be made from second-class 

 cream. 



4. Pasteurization enables the buttermaker to produce an improved 

 quality of butter from infei'ior milk, but it does not improve butter made 

 from perfect milk. 



5. Other advantages are, more uniform quality and better keeping 

 quality in the butter, less loss of fat in the skim milk by pasteurizing 

 before separating, and a better quality of skim milk for the patrons. 

 Where pasteurization at 1S5 degrees is followed there is no danger of 

 spreading tuberculosis among all the herds from one infected herd, as 

 185 degrees will kill the germs causing this disease. 



Disadvantages of pasteurization: 



1. Extra cost for machinery, fuel, labor, etc., which will probably 

 amount to one-eighth to one-fourth a cent per pound of butter. Some 

 claim that it can be done for one-tenth of a cent per pound, but this 

 is probably too low. 



2. Overripe (more than .2 per cent, acid) milk or cream is apt to 

 coagulate when heated and give trouble. Extra care is needed in receiv- 

 ing the milk, and sour milk should be sent home. 



3. Froth sometimes causes considerable annoyance, especially at the 

 high temperature. 



4. The butter tends to lack flavor for local trade, and there is some 

 danger of cooked flavor at the high temperatures. 



