DAIRY FARMING DAIRYING. 399 



supplied witli this mild, well-ripened cheese, oonsuniption will be greatly stimulated, 

 not only by increasing the amount used by present consumers, but by largely extend- 

 ing the use of this valuable and nutritious article of food. The improvement in 

 quality of cold-cured cheese, the enhanced keeping quality, and the material saving 

 in shrinkage due to lessened evaporation are sufficient to warrant a considerable 

 expenditure on the part of cheese producers in installing cold-curing stations." 



Tlte msterii experiments, L. L. Van Slyke, O. A. Smith, and E. B. Hart (pp. 71-88).— 

 In these experiments representative cheeses were obtained from New York, Penn- 

 sylvania, and Ohio, and placed in storage in New York City at temperatures of 40, 

 50, and 60°. The cheeses were examined by a committee of experts when placed in 

 cold storage and after 10, 20, 28, and 35 Aveeks. Chemical analyses were also made. 



"The loss of w^eight increased with increase of temperature, being on an average 

 in 20 weeks 3.8 lbs. per 100 lbs. of cheese at 40° F., 4.8 lbs. at 50° F., and 7.8 lbs. at 

 60° F. The large-sized cheeses lost less weight per 100 lbs. than those of smaller 

 size. Cheese cured at 40° F. was superior in quality to the same kind cured at higher 

 temperatures. That cured at 50° F. was superior in quality to that' cured at 60° F. 

 The general averages of the scores at the end of 20 weeks were as follows: 95.7 at 40° 

 F., 94.2 at 50° F., and 91.7 at 60° F. The difference in quality was confined in most 

 cases to flavor and texture, the color and finish being little or not at all affected in 

 cheese that was in good condition at the beginning. The commercial qualities of 

 cheese were favorably influenced after 6 months in the case of that covered with 

 paraffin, especially in flavor. The loss of moisture was greatly lessened, amounting 

 only to a fraction of a pound for 100 lbs. of cheese at 40° and 50° F., and being only 

 about one-fifth the average loss found at 60° F. with cheese not so treated. The 

 cheeses were also perfectly clean and free from mold, while all the cheeses not treated 

 with paraffin were covered with mold." 



The paracasein monolactate, averaging 57.47 per cent of the nitrogen in cheese 1 

 and 2 weeks old, decreased with the age of the cheese and more rapidly at higher 

 than at lower temperatures. This decrease was accompanied by a corresponding 

 increase in the percentage of nitrogen in form of water soluble compounds. The 

 formation of amido and ammonia compounds possibly associated with the develop- 

 ment of flavor in cheese increased with temiierature and the age of the cheese. 



Experiments in curing cheese at different temperatures, L. L. Van Slyke, 

 G. A. Smith, and E. B. Hart {New York State Sta. Bui 234, pp- 97-m).— This is the 

 same report as that noted above under the subtitle The eastern experiments. 



Cold cured cheese, II, F. H. Hall, L. L. Van Slyke, G. A. Smith, and E. B. 

 Hart {New York State Sta. Bid. 234, popular ed., pp. 7) . — A popular summary of the 

 above. 



Rennet enzym as a factor in cheese ripening, L. L. Van Slyke, H. A. Hard- 

 ing, and E. B. Hart {New York State Sta. Bui. 233, pip. 67-96). — The agencies so far 

 known to take part in the normal ripening of cheese are stated to be (1) acdd, usually 

 lactic; (2) enzyms present in the milk; (3) an enzym in the rennet extract added to 

 milk in cheese making; and (4) micro-organisms, chiefly bacteria. The investiga- 

 tions here reported were concerned mainly with the rennet enzym, the object being 

 to ascertain to what extent this ferment causes the formation of soluble nitrogen 

 compounds in cheese during the j^rocess of ripening. 



In order to study the action of the rennet enzym apart from the other agencies, the 

 milk enzyms were destroyed by heating, a method shown by exi:)eriments to ]yQ 

 effective, and the growth of micro-organisms was prevented by the use of chloro- 

 form. The coagulability of the milk was restored by the use of calcium chlorid or 

 carb(jn dioxid. The action of the rennet enzym was studied (1) in the presence and 

 absence of acid and of salt in cheese made from milk which had been heated to 

 destroy the milk enzyms and treated with chloroform to prevent the growth of 

 micro-organisms; (2) in the i)resence of acid and liquefying organisms in cheese 



