Department of Dairy Industry. 



437 



the tube is replaced. Then allow the clamp to tighten. On loosening 

 the clamp again, the solution will run into the burette. 



8. The small dropper-bottle contains a solution of phenolphthalein. 



B. Making the test. — Measure with the pipette 17.6 c.c of the substance 

 (milk, whey, cream or starter) which you wish to test, and place it in 

 the white cup. Add two drops of the phenolphthalein solution. Then 

 allow the alkaline solution to run into the cup from the burette, one drop 

 at a time, until the fluid in the cup, 

 which is being constantly stirred, shows 



a very faint pink color. By reading the / /^il' x ["i i^ofrk 



graduations on the burette we can ascer- 

 tain the amount of acid in the sub- 

 stance tested. Each cubic centimeter of 

 alkali used represents .01% of acid in the 

 fluid. 



C. Amount of acid to he developed at 

 each stage. — In cheese-making. — 



.20 to .21 % before adding rennet. 



.14 to .145% before cooking. 



.16 to .18 % before removing whey. 



.22 to .24 % when all whey is removed 

 and curd is packed. 



.65 to .75 % before milHng. 



.90 to 1.10% before salting. 



.70 to .80 % in starter. 



In butter -making. — The acidimeter is a 

 great help in securing a uniform flavor in butter. The amount of acid 

 should vary with the amount of butter-fat in the cream. 



% jat. % acid. 

 20 72 



1 1 \Mder 



pipeTTe 



^cc burette 



&tirnng 

 Uod 



iiAihite Cup 



30' 

 40, 



50 



•63 

 •54 

 •45 



D. Precautions. — 



1 . Do not place the colored solution in the sunlight. 



2. Do not use any solution that has been in the burette over night. 

 It will have lost its strength. 



3. Keep corks tight. 



