208 PASTEURIZATION 



said that the Danish butter was mild in flavor and uniform in 

 quahty; in other words, it suited the trade and that was all that 

 was wanted. 



Efficient pasteurization not only enables the manufacturer 

 to inake a more uniform grade of butter, but it makes the butter- 

 milk safe to feed to live stock, thus preventing the spread of 

 infectious diseases. It is said by some that if pasteurization were 

 adopted more skill would be required on the part of the butter- 

 maker. With valves for controlling the steam pressure and the 

 use of recording thermometers, uniform pasteurization to any 

 desired temperature can be brought about by a maker of ordinarv 

 skill, if he applies judgment to the details of his creamery opera- 

 tion. 



Methods of Pasteurization. — At the present time there are 

 three methods of pasteurization employed for butter-making. 

 The one most generally used is the flash or instantaneous heating 

 method. Under this method the cream is heated to a high 

 temperature, i8o° or 185° F., and quickly cooled, by passing 

 over a cooler, to ripening temperature or to churning tempera- 

 ture, as the case may be. In the vat, or holding, method cream 

 is usually heated to a temperature of 150° to 160° F., held at 

 this temperature for twenty to twentj'-iivc minutes, and cooled 

 to ripening or churning temperature. Some use the combinefl 

 flash and holding method. 



Some of the best creameries that use the flash method, or high 

 temperatures, follow what is known as the double system of 

 pasteurizing. Two pasteurizers arc attached to each other; 

 the cream passes to the first pasteurizer from the forewarmer, 

 where it is heated to a temperature of about 135'' or 140° F. It 

 passes from the first to the second pasteurizer where it is heated 

 to 185"^ F., or any temiieralure desired. The live steam is con- 

 nected with the second ])asteurizer, and the exhaust steam from 

 the second pasteurizer furnishes heat for heating the cream in 

 the first pasteurizer to 140° F., or thereabout. The heating of 

 the cream in the first [lasteurizer increases the fluidity of the 

 cream. Hence, when it enters the second pasteurizer, the heat 

 comes in contact with all particles of the cream, and the efficiency 



