568 



STATE BOARD OF AGRICULTURE. 



COMPARISON OF METHODS 



To determine to what extent the pH and the more common methods of 

 testing milk might be used to predict its actual keeping quality when stored 

 at room temperature, 115 samples were collected at a city milk plant as 

 delivered by the farmer patrons and tested as follows : 



Keeping Quality. Milk was held at room temperature and tasted every 

 two hours to detect the first appearance of souring. 



pH Test. Tests were made and samples given a score as described in 

 an earlier part of this paper. 



Reductase test. Applied as described by Hastings (6). 



Bacteriological count. Made according to the Standard Methods of 

 Bacteriological Analysis of Milk. A. P. H. A., 1919. 



The results of these tests are tabulated in Table VII. 



Table VII 



A comparison of the keeping quality of milk, pH score, reduction time and 



bacteriological count. 



