182 CONDENSED BUTTERMILK 



During the early stages of the condensing process the but- 

 termilk boils and behaves in the pan in a, similar manner as 

 milk. As the process continues and the buttermilk increases 

 in density, it becomes more sluggish and does not circulate as 

 rapidly, nor boil as vigorously. 



Concentration. The buttermilk should be condensed until 

 it has a concentration of at least 4:1. Buttermilk of a lower con- 

 centration fails to have the necessary keeping quality to with- 

 stand the trials of storage for several months at ordinary tem- 

 perature. It undergoes decomposition, usually of the putrefac- 

 tive type, that renders it unfit for feeding purposes. 



Testing for Density. No accurate mechanical method of 

 determining the exact density of the condensed buttermilk has 

 as yet been worked out. When a concentration of about 4:1 

 or more has been reached, the buttermilk is very thick, even 

 while hot. It is too thick and viscous to permit of testing it 

 with the Beaume hydrometer. The density could be determined 

 however by weighing a definitely measured volume or by the 

 adaption of a resistance tester such as the Mojonnier viscosi- 

 meter. Ordinarily, however, the determination of the proper 

 degree of concentration is left to the experienced eye and judg- 

 ment of the pan operator. If he condenses batches of uniform 

 size, the height of the surface of the condensed buttermilk in 

 the pan furnishes an approximate guide. The behavior of the 

 boiling condensed buttermilk, when the proper degree of concen- 

 tration has been reached, is also noted. And samples taken 

 from the pan and examined for thickness, standing-tip properties 

 and transparency or opaqueness, as described under "Methods of 

 Striking 11 for sweetened condensed milk, Chapter VI, enable the 

 operator to approach a fairly uniform density of the finished 

 product from batch to batch. 



When condensed at the ratio of 4:1 the buttermilk at the 

 temperature of the pan, or about 120 degrees F., is thick enough 

 so that when a sample is taken into a cup and a portion of it 

 is picked up with a spoon or stick and is allowed to drop back 

 into the cup from a height of about six inches, it does not readily 

 diffuse, but "'piles up" on the surface of the sample in the cup. 



Condensing Buttermilk by Film Process. The condensing 

 of buttermilk can be and is accomplished also by film evapora- 



