116 



MANUAL OF MILK PRODUCTS 



Fig. 14. — The 

 combined acid bottle 

 for rapid work. 



Fig. 15. — 

 The 17.5 c.c. 

 acid cylinder. 



milk, 55 degrees F. to 70 degrees F. In order to insure the 

 proper temperature of the acid it is advisable to set the acid 



bottle into the tank containing 

 the milk sample bottles. 



Add 17.5 c.c. of acid to the 

 milk in the test bottle and 

 mix by giving the bottle a 

 rotary motion until the lumps 

 of curd are completely dis- 

 solved and the mixture pre- 

 sents a black color. It is 

 advisable to add the acid in 

 about three installments, shak- 

 ing the bottle after each ad- 

 dition. Attention to this precaution helps to secure clear 

 tests. 



Whirling and adding ivater (Figs. 16-21) 



Set the test bottles into the Babcock centrifuge. If the test 

 bottles containing the mixture of milk and acid are held over 

 and allowed to become cool, they should 

 be heated by setting in hot water 

 before whirling. 



Steam turbine 

 and electric 

 driven testers 

 with not less 

 than twenty- 

 four pockets are 

 best adapted for 

 factory use. 



They are constructed of two general sizes, — those having a 

 twelve-inch diameter wheel and those having an eighteen-inch 

 diameter wheel. 



Fig. 16. — In pouring 

 acid into the test bottle, 

 incline the bottle a little, 

 to avoid spilling acid on 

 the hand. 



Fig. 17. — To mix the 

 acid and milk whirl the 

 bottle in a circle until 

 the contents are of a uni- 

 form brown color. 



