CONDENSED BUTTERMILK 143 



ate, sodium bi-carbonate, milk of lime, ammonium hydrate, and 

 ammonium carbonate. 



Since one of the virtues, for which buttermilk is of special 

 value for feeding purposes, is its relatively high content of lactic 

 acid, it is obvious that by neutralization the manufacturer is 

 robbing the condensed buttermilk of the very ingredient thai 

 renders it most wholesome and dietetically valuable. 



Furthermore, while, with the exception of milk of lime, these 

 alkalies add nothing to the product that is of acknowledged bene- 

 fit as a food, the addition of caustic alkalies in quantities suffi- 

 cient to reduce the precipitation of the curd and to prevent its 

 sticking on to the pan, is detrimental to the wholesomeness of 

 the finished product. 



There are now several firms in this country who claim to 

 have perfected a method of condensing buttermilk in vacuo, that 

 eliminates most of the difficulties formerly encountered and the 

 expensive copper pan is being replaced for this purpose by one 

 of cheaper material. 



Evaporation by Blowing Hot Air through the Buttermilk. 



This refers to the Campbell process of making concentrated milk 

 as described on page 132. This method has not come into general 

 use and its practicability for concentrating buttermilk is as yet 

 untried. 



Evaporation by the "Continuous Concentrator." There is 



every reason to believe that the use of the "Continuous Concen- 

 trator" for condensing buttermilk is a commercially practical 

 proposition. Experiments have demonstrated that a condensed 

 buttermilk of very good quality can be made by this process and 

 a very high degree of concentration can be accomplished. It is 

 probable that the future will see many of these machines installed 

 in creameries for the purpose of condensing buttermilk. See also 

 "Condensing Milk by the Continuous Process," pages 133-141. 

 Concentration by Centrifugal Separation. For many years, 

 efforts have been made to remove the water from the buttermilk 

 by centrifugal separation. Machines are now on the market and 

 in use, in which the curd of the buttermilk collects on the walls 

 of a revolving basket while the whey is centrifuged out. These 

 machines are similar in principal to the well-known laundry 

 centrifuge. They have been successfully used by creameries that 



