96 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



CONDENSED MILK. 



Investigations of condensed milk have been carried on along 

 three different lines, namely, the cause and control of "buttons" 

 or reddish lumps occurring on the surface of condensed milk, the 

 (quantity of sugar necessary to preserve milk, and the factors affect- 

 ing viscosity. In the first study it was demonstrated that "buttons" 

 are caused by the action of molds and that by careful attention 

 to the source of infection the trouble can be prevented. Progress 

 has been made on a study to determine the concentration of sugar 

 essential to the preservation of milk. The principal factors influ- 

 encing the viscosity of milk, both when freshly condensed and after 

 standing, have been determined. An investigation is under way 

 also to determine the influence that certain factory conditions have 

 upon these factors. 



MANUFACTURE AND RIPENING OF CHEESE. 



The methods of manufacture of cheeses of the Roquefort, Camem- 

 bert, and Swiss types have been so developed that it is the intention 

 to manufacture these products on a commercial scale at Grove City, 

 Pa., as soon as the addition to the creamery is completed. Improved 

 methods for making Neufchatel, cream, and cottage cheese have 

 been developed so as to make a more uniform and higher-quality 

 product, and it has been found possible to make the last-named 

 cheese from a mixture of high-grade buttermilk and skim milk. 

 Parmesan, a low-fat cheese, is being studied at present with a view 

 to determining whether it is possible to make it satisfactorily in 

 this country. 



An organism has been isolated from Swiss cheese which has not 

 previously been described and which apparently produces the "eyes" 

 or gas cavities characteristic of that cheese. There is good reason 

 to believe that this new culture can take the place of the starter 

 made from old cheese and that its use will result in a more uniform 

 grade of cheese. Cultures have been isolated from Cheddar cheese 

 which produce the characteristic Cheddar flavor in cheese made 

 from pasteurized milk, and similar cultures have been used to con- 

 trol the flavor of cream cheese, 



CREAMERY BY-l'-RODUCTS. 



Much time and effort has been spent in developing factory methods 

 for the manufacture of casein from skim milk and buttermilk. Since 

 casein is one of the important constituents of the waterproof glue 

 needed in the use of "pl3rwoods" in the airplane and other industries, 

 studies are being made in cooperation with the forest products 

 laboratory to determine whether it is possible to manufacture a 

 high-grade casein from medium and low-grade buttermilk. These two 

 toriii the only abundant supply available, since high-grade buttermilk 

 and skim milk are now used lar:;ely lor huiuan food. If it is found 



f)0ssible to purify lo\v-T;rado buttermilk or the resulting casein made 

 roni it, an abundant and cheap supply of casein will be available. 



Studies of the utilization of whey are in progress to deter.'riine 

 whether priinost of good quality can be made from whey of high 

 acidity. 



