200 CANADIAN DAIRYING. 



from a graduated burette slowly add the alkaline 

 solution, stirring the cream all the, time with a glass 

 stirring rod. When the cream turns a pink color 

 throughout the whole mass, the acid is neutralized. 

 Now count the number of c.c. of alkali used and this 

 represents the percentage of acid in the milk or 

 cream in tenths ; e.g., ten c.c. cream is used for a test 

 and this requires 5.6 c.c. of alkaline solution to 

 neutralize the acid, then the percentage of acid in the 

 cream is ,56. By having the alkaline solution of this 

 strength it saves the trouble of figuring as required 

 with a one-tenth normal solution and there is less 

 danger of error. 



When ready to churn the cream should have from 

 .5 to .6 per cent, of acid the smaller amount for: 

 export butter. Very rich cream, or cream containing 

 a high percentage of fat, should not have quite so, 

 much acid as thin cream, or cream containing a low 

 percentage of fat. In creamery practice this is not 

 an important point. The percentage of acid, how- 

 ever, : may vary considerably without affecting tjie 

 quality of the butter very much, so long as the flavor 

 is clean and there are no abnormal fermentations. If. 

 the buttermilk contains about .8 per cent, of acid it 

 will be about right for local .markets. For export 

 butter the buttermilk should not have more than .6; 

 to .7 per cent, of acid, as a milder flavor is liked in 

 such butter; . 



The ripening of cream consists chiefly in the devel- 

 opment of the lactic acid by suitable bacteria, which 

 causes coagulation of the casein when there is about .4, 



