104 Condensed Milk and Milk Powder 



Since the great bulk of butter is manufactured during the sum- 

 mer season the main supply of buttermilk is confined to the summer 

 months. In summer the output of -buttermilk far exceeds the de- 

 mand for this product and much of it goes to waste for lack of a 

 suitable market for it. In winter, on the other hand, the output of 

 buttermilk is small and insufficient to supply the demand. 



In order to stop this waste of buttermilk in summer, to utilize 

 it economically and profitably and to equalize the supply throughout 

 the year, some of the large creameries of the country have found 

 it practicable and profitable to condense the surplus buttermilk. 

 Information from chicken feeders shows that, when re-diluted to 

 the consistency of the original buttermilk, this condensed buttermilk 

 gives equally as satisfactory results as the fresh buttermilk. 



Manufacture. — Buttermilk is condensed in vacuo in the same 

 manner as plain condensed bulk milk; or in open vats by passing a 

 current of hot air through it, similar as in the case of concentrated 

 milk. The latter process has the advantage, because it involves but 

 little additional equipment by the creamery and can readily be oper- 

 ated by the usual creamery personnel. The ratio of concentration 

 is about 4 to 5.5 :i ; i. e., from four to five and five-tenths parts of 

 buttermilk are condensed to one part of condensed buttermilk. 



The; Use op Neutralizes in the Manufacture oe Con- 

 densed Buttermilk. — The condensed buttermilk has a grainy body. 

 This is due to the action of acid and heat on the casein, contract- 

 ing the curd and making it hard, dry and grainy. If the acid in the 

 buttermilk is neutralized by an alkali the body of the condensed but- 

 termilk is smooth and homogeneous. 



The most common alkalies used for this purpose are sodium 

 bi-carbonate and milk of lime. These adulterants are easily de- 

 tected by the chemist. In order to more successfully hide the use 

 and presence of alkalies in condensed buttermilk, ammonium hy- 

 droxide and ammonium carbonate are frequently employed instead. 



Since the lactic acid in the buttermilk is one of the desirable 

 ingredients, enhancing its wholesomeness and dietetic value, it is 

 obvious that, by neutralizing this acid, the manufacturer is robbing 

 his product of one of the chief virtues for which it is valuable. 



Furthermore, while, with the possible exception of milk of 

 lime, these alkalies add nothing to the milk that can be of any benefit 



