METHODS OF BEDUCING THE GERM CONTENT 



515 



came to the following conclusions: "At 70° C. (158° F.) the effi- 

 ciency of the continuous pasteurizer varies greatly from day to 

 day. Tests upon fourteen different days gave an average of 15,288 

 living germs per cubic centimeter left in the pasteurized milk, 

 with a maximum of 62,790 and a minimum of 120 germs. At 

 80° C. (176° F.) the reduction in germ content is both very uni- 

 form and very great. Tests upon twenty-five different days gave 

 an average of only 177 Hving germs per cubic centimeter in the 



M/L/< /A/LCT 



REVOLVWC COVeR 

 CAffRY/NG TAPE 



HEAT/f^G CONS 



Fig. 201. — Conical tjrpe of simple pasteurizer. (S. H. Ayers in Circular 184, 

 Bureau of Animal Industry, U. S. Dept. of Agriculture.) 



pasteurized milk, with a maximum of 297 and a minimimi of 20 

 germs. At 85° C. (185° F.) the average reduction is not more 

 marked than at 80° C, but the range of variation is less. This 

 temperature has the added advantage, according to Dr. Bang, of 

 removing the danger from germs of tuberculosis in the milk. 

 Even when the whole milk was heated to 85° C. the butter did not 

 have a permanent cooked flavor." 



It has been found that heating milk to 85° C. has serious dis- 

 advantages, the most important of which is the reduction of the 



