DATRY FARMING DAIRYING. 579 



held at St. Paul, Minn,, 190S, was as follows: Water 12.54, fat 84.65, salt 1.77, 

 and casein and ash 1.02 per cent. 



Acidity of creamery butter and its relation to quality, ('. IjArsen, T, H, 

 Lund, and L. F. Miller {Hoiith Dakota i^ta. Bui. 116, pu. 573-594). — This is a 

 study of the relationship between the quality and acidity of butter. 



Several methods of testing butter for acidity were tried. The use of hot 

 water at different temperatures was found to be less satisfactory than the 

 ether and alcohol method. Gasoline and benzin were found unsatisfactory. The 

 provisional official method gave lower results than the ether-alcohol method, 

 especially in fresh butter, since it showed the acid in the fat only, while the 

 ether-alcohol method showed the acid in all the constituents of butter. Another 

 reason which in a measure accounts for the lower results by the provisional 

 method is the high temperature of the fat at the time the test is made. 



The acidity of the fat in fresh butter was found to be slightly greater than 

 that of an equal weight of clear brine but less than that of an equal weight of 

 curdy brine. In 16 samples of butter 12.S ])er cent of the acid was in the brine 

 and the remainder in the fat. 



When butter from various sources was scored and tested for acidity, the 

 average relation between score and acidity of 305 tubs was as follows: In 99 

 tubs scoring 93 and above the average acidity, measured in cubic centimeters 

 tenth-normal alkalis, was 1.97; in 158 tubs scoring 89 to 93, 1,93; and in 48 

 tubs scoring below 85, 2.08. 



" From these results it will be noticed that there is little or no uniform rela- 

 tion existing between the quality and the acidity of fresh butter, . . . The de- 

 fects associated with the body, color, and salt, and the flavors of a nonacid 

 character, none of which can be measured by an acid test, evidently constitute 

 the chief faults of fresh butter. When fresh butter has once been judged and 

 a certain score put upon it, and the same butter retained to be tested for keep- 

 ing quality, experiments completed, and others now in progress, show that an 

 acid test is by far the better criterion as to the extent and rapidity of dete- 

 rioration," 



Pasteurization as a factor in making' butter from cream skimmed on the 

 farm, C, E. Lke (lUinois t>1a. Bui. 138, p[). 3(i\)-Ji3S). — ^This is a study of the 

 quality of butter made from pasteurized sour cream as compared with the 

 qualitj' of butter made from the same grade of cream not pasteurized. 



The butter scored in 1905 gave an average of 0.7 of one point higher score in 

 favor of butter made from pasteurized cream. After being in cold storage 4 

 months the butter from the unpasteurized cream decreased in quality 0.3, and 

 that from the pasteurized 0.45, of one point. In 1900 butter made from un- 

 pasteurized cream scored on an average 0.5 of one point over that of the pas- 

 teurized. Twentj^-six days later the same lot of butter was again scored by 

 two judges, with an average of 0.97 and 0.27 of one point, respectively, in favor 

 of the unpasteurized. After being in storage 101 days one judge decided that 

 there was no difference in the decrease of quality, while the score of another 

 judge showed that the butter from the pasteurized cream had decreased 0.71 

 of one point more than the butter from the unpasteurized. 



" The 104 tubs of 1907 butter were scored by five judges 44 days after the 

 first lot was made. According to three of these judges the unpasteurized but- 

 ter scored higher by 0.56. 0.27 and 0,10 of one point respectively. The other 

 two judges scored the pasteurized butter higher by 0.3 and 0.41 of one point. 

 Following a period of four months in storage this butter was re.scored by four 

 of the former judges. According to three of them the unpasteurized decreased 

 in quality 0.13, 0,72 and 0.04 of a point more than the pasteurized butter, while 

 the fourth judge scored the unpasteurized butter higher by 0.34 of one point. 



