METHODS OF PASTEURIZATION 209 



of pasteurization is thereby increased. From general observa- 

 tion of work in many creameries belonging to the American 

 Association of Creamery Butter Manufacturers, the authors 

 feel safe in recommending this system. 



One of the authors first saw this system in general use at the 

 Experiment Station at Kiel, Germany, something over twenty 

 years ago. Dr. Weigman was heating to 190 F. at that time, 

 and claimed very satisfactory results. 



The relative merits of the two systems the vat system where 

 the heating is done through a coil, or the use of a machine con- 

 structed exclusively for pasteurizing milk and cream depend 

 largely upon local conditions. If the first cost only is taken 

 into consideration, cream can be pasteurized more cheaply under 

 the vat system, as the heating and the cooling are done in the 

 same vat. In a small creamery where space has to be taken into 

 consideration, the vat system is to be recommended. Not only 

 does it require less space but it involves less labor. The objections 

 to the vat system are, first, that the vat is not constructed for a 

 pasteurizer, and, second, that the wear and tear (heating and 

 cooling, and expansion and contraction) will affect the life of 

 the vat. These are items that must be taken into consideration 

 when figuring the cost over a period of years. In a factory where 

 a large volume of business is transacted, the regular pasteurizer 

 would be preferable. It is much stronger than the vat and is 

 constructed exclusively for the purpose of pasteurizing cream. 

 In addition to this a greater amount of cream can be cared for in a 

 shorter space of time. The cooling is done much more quickly 

 where a regular cooler is used. Another advantage is that the 

 heating and cooling are not done in the same vat, thus avoiding 

 the expansion and contraction of the metals. 



Some use the method of heating in the flash pasteurizer and 

 cooling in a vat. This does away with the necessity for a cooler, 

 but, as stated above, the cooling is not done as rapidly as it would 

 be if a regular cooler were used. This system works well where 

 the holding system is practiced and lower temperatures are used 

 for pasteurizing. Cream can be run into the ripening vat from 

 the flash pasteurizer, held any desired time and cooled with a coil. 



