648 



TESTING BUTTER 



Operation of Test. This test is intended to be a continuation 

 of the moisture test in which an evaporating dish of a diameter of 

 2^ inches is used. 



(1). At the conclusion of the moisture test fill the 100 c.c. cylin- 

 der to the mark with warm water, temperature about 100 F., and 

 pour this water into the salt tester. 



(2). Invert moisture evaporating dish over rubber ring of salt 

 tester and make the dish fast by means of wire clamp. 



Tig. 109. Hunziker Salt Tester 

 and Evaporating* Dish 



rig-. 110. Hunziker Salt Tester 

 Beady for Shaking 1 



(3). Now shake the salt tester vigorously, giving it about 30 

 shakes. This causes the salt in the evaporating dish to be washed 

 out by the warm water. 



(4). Remove evaporating dish and transfer with pipette 25 

 c.c. of the salt solution from the salt tester into the titrating flask. 



(5). Add 1 c.c. of potassium chromate solution to the titrat- 

 ing flask and from burette slowly add silver nitrate solution until a 

 permanent brick-red precipitate is obtained. The titrating flask 

 must be constantly and thoroughly agitated by a rotating motion 

 while the silver nitrate solution is added. 



(6). If a 10-gram sample of butter is used in the moisture test, 

 each c.c. silver nitrate solution represents .1 per cent salt. Assum- 

 ing that 35 c.c. silver nitrate solution was used, the butter then con- 



. 35 



tained = 3.5% salt. 

 10 



