r.'19] DAIRY FARMING DAIRYING. 675 



Studies in processing milk, II. V. Jidkins nntl P. A. Downs (Conm < ti< ut 

 Stom Sta. Bui. 99 (1918), pp. U9-470).—The various Btudlea Included in this 

 bulletin deal chiefly with clarification, pasteurization, and cooling after pas- 

 teurization, wiih particular reference to bacterial count and the cream Una. 



The clarification of both raw and pasteurized milk was found t<> cause an 

 apparent Increase in the bacteria count. The clarification of raw milk produced 



nn average reduction in the cream line of 0.4.''> per cent, While in the case of 

 pasteurized milk the reduction was 0.9 per Cent The reduction in both cases 

 is so Slight that it would he Impossible to detect it in the ordinary milk bottle. 



Very little difference was found between the vat ami the In-bottle methods of 

 pasteurization in regard t<> bacterial efficiency. The average efficiency for the 



vat is 99.95 per cent and for in bottle pasteurization 99.96 per cent. The re- 

 duction in Cream line id' vat pasteurized milk when cooled in the vat was 2.9 

 per cent and when cooled over the cooler 1.5 per cent. Both reductions are so 

 small that they would scarcely be noticed on bottled milk. In the case of in- 

 bottle pasteurization there was no apparent reduction in the cream line. 

 The higher the temperature to which the milk was heated the greater was the 

 reduction in cream line. In vat pasteurization this reduction was found to take 



place mostly during the holding and cooling process. 



The time and water required for cooling were slightly lower in the case of 

 the vat cooling. The latter is also considered preferable because less equip- 

 ment is needed. The air blast method of cooling in-bottle pasteurized milk is 

 regarded as very satisfactory. The vat and the in-bottle methods of cooling 

 were both found ideal as far as the bacteria count is concerned. The cooler 

 method showed an average increase of 3.GG4 bacteria per cubic centimeter in 

 milk passing over it. 



The pumping and bottling of pasteurized milk with equipment cleaned in the 

 ordinary manner is considered a great source of recontamination. In the tests 

 an increase of 11,755 bacteria per cubic centimeter was due to the pump and 

 pipe line while the bottler added 35,838 per cubic centimeter more. Milk pas- 

 teurized in the bottle showed a bacteria content of 352 per cubic centimeter, 

 while the same milk pasteurized in the vat showed 439 per cubic centimeter. 

 This same milk bottled showed an Increase of 47, .V.) I bacteria per cubic cen- 

 timeter, a large percentage of which were liqueliers. The use of chlorid of 

 lime solution in (lushing out all equipment before processing milk was found 

 to do away with practically all recontamination of milk after pasteurizing. 



The manufacture of small cheese with improvised apparatus {Jour. B4, A<ir. 

 [London], 25 (1918), No. •>'. pp. 269-277, fig. 1). — A procedure in making cheese 

 on the farm is outlined involving the use of no material not commonly available 

 on dairy farms except a thermometer, rennet, and cheese molds. 



Neufchatel cheese, H. S. Baird (California sta. Oirc. .!<>1 {1919). pp. .',. flga, 

 2). — Brief directions are given lor the manufacture of Neufchatel cheese. It 

 is said that it can be made satisfactorily from cow's milk, but goat's milk is 

 preferable. Its manufacture affords an outlet for surplus milk, as the necessary 

 apparatus for making the cheese on a small scale is not expensive. 



Experiments in ice cream making-. A. C. Bakk (Oklahoma sta. Rpt. 1918. 

 I>. SI). — In a Study of two types of emulsifying machines for ice cream mixes. 

 a centrifugal emulsifier gave uniformly better results than a steam emulsi- 

 fler. It was found that the steam emulsifier adds from 10 to 15 per ceut of 

 water, due to condensation of steam which is turned directly into the cream. 

 This reduces the percentage of total solids in the mix as well as the butter fat. 

 Milk solids can be added in the form of milk powder or condensed milk. 



The emulsified milk and emulsified mixes made from butter and skim milk or 

 butter, skim milk powder, and water are found to produce excellent ice cream 



