506 EXPERIMENT STATION RECORD. 



to niu'-tliinl. l^y rvihu-\i\'^ the flow of milk to this I'xtcnt the fat coiitcut of tlic skiiu 

 milk from old milkers was reduced to about oue-teuth, wlicii the separatioii took 

 place at 50° or above. — f. \\. avoli,. 



A hitherto unexplained cause of poor skimming', C. Bahthel {Laiidtmannen, 

 14 {IDOd), No. 20, pp. .Ul~.il5; Xord. Mejeri Tidii., 18 {190S), No. 18, pp. 235, 236).— 

 It was found that milk which was emptied out of a pasteurization apparatus by 

 means of a steam injector gave a skim milk nmch richer in fat when separated than 

 milk whii;h was run through the pasteurization ai)paratus without pressure; the fat 

 contents of the 2 kinds of skim milk, as determined by the Gottlieb method, being 

 on an average 0.31 and 0.13 per cent, respectively. 



In investigating the sutjject the author found that violent agitation of the milk at 

 separating temperatures caused a division of the fat globules, the minute globules 

 remaining in the skim milk in the process of separation. Milk churned for 5 min- 

 utes at 50° C. and afterwards pasteurized at 75°, gave skim milk containing 0.69 per 

 cent of fat, against 0.12 per cent found in skim milk from milk not previously 

 churned. When the milk was churned at a very low temperature (5.5°) for 5 min- 

 utes, a similar fat content was obtained as in the case of the skim milk from milk not 

 previously churned. Similar results were obtained in a number of different trials. — 



F. W. WOLL. 



Influence of pasteurizers on clean skimming, T. Berg {Lundtmunncn, 14 

 {1903), No. 29, jip. 460-462). — The results of the work by Barthel, noted above, have 

 been corroborated Ijy the author. In experiments with a steam turbine pasteurizer 

 no increase in the fat content of the skim milk was observed when the stirrer was 

 turned at a speed of 200 to 250 revolutions per minute; but with 300 to 500 revolu- 

 tions an increasing amount of fat remained in the skim milk, the average percentages 

 in the 2 cases being aVjout 0.118 and 0.225 per cent. In trials with milk pumps no 

 appreciable difference was obtained in the fat content of the skim milk, whether the 

 milk passed through the i:)ump at 50 or at 17°. — f. w. woll. 



Influence of clean skimming on the yield of butter, T. Beko {Nord. Mejeri 

 Tidn., 18 [lHOo), No. 22, pp. 301-303). — Experiments conducted by the author showed 

 that a decrease in the fat content of the skim milk from 0. 223 to 0. 147 per cent increased 

 the amount of butter obtained from 50 kg. of milk from 1.691 to 1.734 kg., or 0.043 

 kg., while a further decrease in the fat content of the skim milk from 0.147 to 0.092 

 per cent increased the yield of butter only 0.022 kg. In the former case the differ- 

 ence in the fat content of the buttermilk was 0.086 per cent, in the latter 0.039 per 

 cent. 



There is apparently a limit below which it does not pay to skim the milk; the 

 nearer this is reached the more expensive the reduction in the fat content of the 

 skim milk becomes. It is shown l)y the results published in the i)aper that 0.01 kg. 

 of butter may be obtained per 100 kg. of milk for every 0.01 per cent of fat more or 

 less in the skim milk. — f. w. woll. 



Influence of clean skimming on the yield of butter, L. F. Rosengren {Nord. 

 Mi'jtri Tidn., 18 {1903), No. 23, pp. 307-309). — The same conclusion was reached as 

 in the work by Berg, noted above, that somewhat more fat is, as a rule, left in the 

 buttermilk by close skimming; but that this is much less than the amount going 

 over into the butter. Of the 88.3 gm. which the cream from 100 kg. of milk in one 

 series of trials exceeded that in another series, 12 gm. remained in the buttermilk 

 while 76.3 gm. went into the butter. The closer skimming reduced the fat content 

 of the skim milk 0.0984 and increased the yield of butter 99.6 gm. Calculated per 

 100 kg. new milk, a decrease of 0.01 per cent in the fat content of the skim milk is 

 equivalent to an increase of 10 gm. in the yield of butter, even if the milk is skimmed 

 so as to leave only 0.05 per cent of fat in the skim milk. — p. w. woll. 



Researches on the fermentation of milk, H. Tissier and P. Gasching {Ann. 

 Inst. Pasteur, 17 {1903), No. 8, pp. 540-363). — In connection with a study of the bac- 



