874 EXPERIMENT STATION RECORD. 



cholerce, B. ttiherculosis, aud coccal groups. Observatious were also made on 

 fat splitting in milk by bacterial lipase. 



Preparation of buttermilk which can be preserved for a long time, R. 

 SuwELACK iOerman Patent 273,628, Jan. 30, 1913; ahs. in Jour. 8oc. Chem. 

 Indus., 33 (1914), No. 14, p. 763). — "Fresh buttermilk is heated for some time 

 at not below 85° C, with vigorous agitation, then rendered homogeneous by 

 forcing it, under a pressure of about 250 atmospheres, through narrow tubes 

 against a hard surface, and after being cooled and freed from air is inclosed 

 in air-tight vessels." 



An investig'ation into the composition of cheese made from whole milk, 

 G. Bkownlee {Dept. Agr. and Tech. Instr. Ireland Jour., IJf (1914), No. 3, pp. 

 499-506). — From tests for fat made of a large number of samples of green and 

 cured cheese it was found that on a dry matter basis " in the Cheddar cheeses 

 the highest and lowest percentages were 53.54 and 48.72, respectively, in the 

 green, and 52.96 aud 48.6 in the cured, while for the Caerphilly cheeses the 

 corresponding figures are 56.79 aud 47.75 for the green, and 57.15 and 47.11 for 

 the cured. The average percentage of fat in the dry matter of all the green 

 cheese samples is 51.49 and of the cured 51.19, while that for all (327) samples 

 is 51.33. . . . Taking the figures here found as a basis, one might safely 

 recommend that a percentage of 45 should be taken as the limit below which 

 the fat in the dry matter of a genuine cheese should not fall." 



It is calculated that " 1 gal. of milk gives 1.3 lbs. green Caerphilly cheese, 

 1.239 lbs. cured Caerphilly cheese, 1.056 lbs. green Cheddar cheese, and 1 lb. 

 cured Cheddar cheese." 



Pasteurized milk cheese {Wisconsin Sta. Bui. 240 {1914), PP- 39, 40). — Con- 

 tinuing work previously noted (E. S. R., 28, p. 581), tests conducted at various 

 commercial factories in making pasteurized Cheddar cheese were satisfactory, 

 an increase in yield of from 3 to 5 per cent being obtained. In some 

 cases the texture was slightly inferior because of small holes. The extra cost 

 of making pasteurized cheese was about $2.25 per 1,000 lbs. Likewise satis- 

 factory results have been obtained in making pasteurized brick cheese. 



Three creamery methods for making buttermilk cheese, J. L. Sammis 

 {Wisconsin Sta. Bui. 239 {1914), PP- 3-24, fiffs. 7). — Complete information is 

 given on three methods of making buttermilk cheese, one of these previously 

 referred to (E. S. R.. 23, p. 181; 25, p. 583), which has been used for several 

 years at creameries and in dairies in making cheese from ordinary buttermilk. 

 The other two deal with the use of buttermilk obtained from cream pasteurized 

 while sour. 



Ice cream investigations {Wisconsin Sta. Bui. 240 {1914), PP- 40, 41, fiV- 

 1). — In studying the factors which govern the overrun or "swell," the body 

 texture, and the flavor of ice cream, A. C. Baer found that " the longer a 

 cream is held cold the more viscous or the thicker it becomes, and the greater 

 is the tendency to produce a high overrun during the freezing process. If the 

 mixture is frozen too quickly, especially at the critical temperature between 

 30-28° F., not enough time is given to whip up the mixture properly and a low 

 overrun will result. For this reason the temperature of the freezing mix- 

 ture should not be too low. 



" For proper whipping of the mixture to produce a good swell, a speed of at 

 least 100 to 150 revolutions per minute is necessary in a freezer of the ordi- 

 nary batch type, and from 200 to 250 revolutions in a continuous machine. Too 

 rapid freezing produces a soggy and course grained ice cream. On the other 

 hand, freezing too slowly may allow too much whipping and thus produce an 

 undesirable open and foamy texture. Aging cream makes it more viscous, 

 thus producing a firmer and smoother ice cream. A raw cream produces a 



