234 



STATE BOARD OF AGRICULTURE. 



effects of other treatments of the butter were also to be observed. These 

 included, (a) washing of the butter with lactic acid, (b) the addition 

 of casein, (c) the addition of lish}^ butter, and (d) the addition of boric 

 acid. 



A single vat of cream was divided into two equal portions, one of 

 which was pasteurized and the other unpasteurized. Each of these 

 portions was further subdivided into two parts, one part being churned 

 "VN'ithout furtlier treatment and the other ripened by the addition of 

 starter. Each of the four divisions of cream was then churned sep- 

 arately. The butter from each churning was tlien divided into five por- 

 tions which were subjected to tlie four further treatments mentioned 

 above, with one of the portions acting as an untreated control. The 

 twenty different butters (about 00 lbs. each) were packed in 30 pound 

 tubs and shipped without delay to a cold storage plant where they re- 

 mained for the duration of the experiment at about 0° F. At inter- 

 vals of 9, 48, 1G4, 275, and 426 days the butters were scored and sampled 

 for bacteriological and chemical determinations. 



The following scheme indicates the divisions of the cream and the 

 treatments of the butters: 



Treatments 



Control 



Acidified H;0 in 2nd washing 



Casein added 



Fishy butter added 



Boric acid added 



Control 



Acidified HaO in 2nd washing 



Casein added 



Fishy butter added 



Boric acid added 



Control 



Acidified H2O in 2nd washing 



Casein added 



Fishy butter added 



Boric acid added 



Control 



Acidified PLO in 2nd washing 



Casein added 



Fishy butter added 



Boric acid added 



While the results of this study failed to reveal any striking proofs of 

 the relationship between methods of manufacture and either the score or 

 the development of definite off-tlavors, yet certain facts stand out suffi- 

 ciently well to warrant mention. Tliey are as follows: 



The raw cream butters quickly develoi)ed the old cream flavor which 

 was later followed bj^ fishy flavor, wliile the i)asteurized (sour) cream 

 butters early developed a metallic flavor. Tallowy flavor developed 

 more frequently in the raw cream biitfers than in Ihe pasteurized cream 

 butters. Acrid flavor developed much moie frc(ju('iilly in well ripened 

 pasteurized butters than in raw butters. From this study there is no 

 evidence that either pasteurization or ripening improves the keeping 

 quality of butters made from cream which has already soured. 



