DAIRY FARMING DAIRYING. 1087 



Experlmenffi in rhecKe makhuj (pp. 41-51). — Data are given for 165 trials showing 

 the yield of cheese from milk containing from 3.4 to 4.8 per cent of fat. One hun- 

 dred pomidsof milk testing 8.4 per cent of fat made 10.15 lbs. of green cheese, or 2.94 

 lbs. for each pound of fat in the milk, and 100 lbs. of milk testing 4.8 per cent of fat 

 made 12.09 lbs. of green cheese, or 2.52 lbs. for each poimd of fat in the milk. On an 

 average 100 lbs. of milk made W.'M lbs. of green cheese, or 2.77 ll)s. tor each ]Kmnd 

 of fat in the milk. The loss in weight in cheese cnre<l at the station for 1 month 

 was 6.94 per cent and for 6 months 9.;W per cent. 



Cheese made by the "dip-curd" jirocess, in which the curd is stirred for 10 or 15 

 minutes after dipping, salted and pressed immediately, cured quickly but was soft 

 and .acked uniformity. It lost 18.5 per cent in weight in 1 month. 



The fat lost in whey averaged 0.15 per cent, practically no difference being 

 observed in this respect in milk testing 3.4 to 4.7 per cent of fat. A temperature of 

 86° F. for renneting was found most satisfactory. In experiments during 1900 

 cheese was cured in (1) cold storage at 45 to 50° F., (2) in a curing room at 60 to 65° 

 for 1 month and then in cold storage, and (3) in the curing room for the whole 

 time, data for the physical examination for the cheeses being given. The loss in 

 weight was practically the same in each case. The results of curing at a low tem- 

 I^erature were not entirely conclusive. 



A study of enzyms in cheese, L. L. V.\n Slyke, II. A. Hardixc, and E. K. TIart 

 {Nev^ York Stalf Sto. Bui. iiOS, pp. 215-244) • — Enzyms in cheese are shown to come 

 from bacteria, milk glands of cows, and rennet. In the investigation here reported 

 bacterial action was for the most part excluded by the use of antiseptics. Of the 2 

 phenomena of cheese ripening, namely, the chemical decomposition of casein and the 

 formation of flavors, the study was concerned chiefly with the former. The literature 

 of this phase of the subject is briefly reviewed, and the methods of chemical analysis 

 used are outlined. 



Chloroform was added to skim milk containing only a trace of fat in amounts vary- 

 ing from 2.5 to 30 per cent by volume and the percentage of nitrogen in soluble forni 

 in the different samples was determined at frequent intervals for 192 days. The 

 bacterial content was small in all cases. In general, there was a marked progressive 

 increase during this period in the amounts of soluble nitrogen, which varied but 

 little in samples treated with different percentages of chloroform, indicating that the 

 restraining action of chloroform upon enzyms is slight. Two series of samples were 

 prepared from whole milk and melted butter fat to contain, respectively, 10 and 20 

 per cent of fat. Chloroform was added to each series in amounts ranging from 2.5 

 to 20 i>ercent. Determinations of the soluble nitrogen and the bacterial content of 

 the samples for 112 days showed practically no influence upon the antiseptit; value 

 of the cldoroform due to the different amounts of fat. The germ content was higher 

 than in the preceding series of exi)eriments, l)ut several reasons for this are offered. 



In one series of experiments with whole milk a comparison was made of the effect 

 of 15 per cent of ether, 3 per cent of chloroform, and a mixture of 2.9 per cent of 

 ether and 2.1 per cent of chloroform upon the activity of enzyms. The increase in 

 soluble nitrogen was more rapid where the ether was used, but the bacterial devel- 

 opment, consisting almost entirely of one kind, was also greater. "This experience 

 has made us slow to accei)t as trustworthy any results obtained with the use of ether, 

 when the conditions are not constantly controlled by quantitative examination of 

 the bacterial content." In another series of experiments a similar comparison was 

 made of 4 per cent of chloroform and 0.1 per cent of formalin. The total soluble 

 nitrogen at the end of 152 days averaged 45.62 percent in the formalin series and 

 60.63 i)er (ent in the chloroform series, showing a greater restraining inlluence of 

 the formalin upon enzym action. The bacterial content in all cases was low. 



In connection with the last series of experiments the relation between bacteria in 

 the udder and enzyms in the milk was investigated. Jt was lound in additional 



