603 



The butter extractor (pp. 24-32). — Ten trials were made with this 

 apparatus. 



The extractor is designed to make butter directly from sweet wliole milk, and is 

 essentially a separattw and a continuous churn combined. The jiroccss diiiers from 

 the sweet-cream process only as to the time the operation lasts (probably not more 

 than a second for any particular drop of milk), and in the lower temperature at 

 which the milk is separated. The work is done by means of a revolving bowl like 

 that of a separator, a device for churning the cream inside of this bowl and another 

 for patching the butter underneath. The milk^ which is fed at the top, is first sep- 

 arated into cream and the cream is churned almost instantly to butter. The butter 

 is received at once into a tub of ice water, from which it is taken and worked imme- 

 diately, and again worked on the following day. 



The results of the two best trials and the analyses of the butter are 

 tabulated. In these 816 and 1,034 pounds of milk were used, contain- 

 ing 3.79 per cent of fat. The percentage of the total fat recovered in 

 the butter was 84.6. In the two trials the average rate of work per 

 hour was 960 pounds of milk and 38.65 pounds of butter. 



A comparison of the efficiency of the extractor with that of the sour-cre.am and 

 the sweet-cream process shows it to be 8.74 per cent below the former, and 3.81 

 per cent below the latter. The difference between the extractor and the sweet- 

 cream process is chiefly due to the greater mechanical losses on the part of the 

 extractor and in smaller degree to less jjerfect separation and less perfect churning. 



To determine how far the higher yield of the sour-cream process is due to difi'er- 

 ence in the churnability of sour cream and sweet cream, the experiment was tried 

 September 8, and repeated November 28, of taking sour or ripened cream, separated 

 by the De Laval separator, and ready for churning by the sour- cream process, 

 adding thereto the corresponding quantity of fresh separated milk, and running 

 it through the extractor just as fresh whole milk. The results seem to confirm the 

 conclusion that butter is more easily and completely separated from sour cream than 

 from sweet cream. 



The trial on sour cream made September 8 gave an efficiency of 86.18 per cent — an 

 increase of 1.58 per cent over the sweet milk runs, and the trial on November 28 

 gave 85.28 per cent. The falling off in the second instance is due to the imperfect 

 separation done by the extractor on that day. 



Hence it seems clear that if the extractor could work on sour cream it might easily 

 increase its efficiency from 1 to 2 per cent. * * * 



An experiment was further tried November 28 to ascertain if the large quantity 

 of butter left in the wash water could not in part be recovered by running the wash 

 water through the extractor just as the whole milk. The result was 80.08 per cent 

 without this addition and 81.74 per cent with it — an increase of 1.66 per cent. 

 Although the gain is considerable it is doubtful if this would be a useful practice, 

 inasmuch as the butter thus recovered appears to be decidedly peculiar. It retains 

 after working, over 27 per cent of Avater; it lacks the cohesive quality of the other 

 butter; and it is whiter in color and less firm. It seems so far inferior to the other 

 butter that it would be impossible to work up the two together without great injury 

 to quality. 



As to the quality of the extractor butter, a point of more importance to the cream- 

 ery man even than the yield, all that was said of sweet-cream butter may be 

 repeated. In some instances strictly first-class buttei', in the opinion of experts, 

 was made when the examination was made at a rather low temperature. The 

 "grain" is considered excellent, fully as good as that of the best grades of sour- 

 cream butter. The taste is the same as that of the sweet-cream butter, to some 

 people agreeable and even preferable to the other. So far as could be observed, 



