332 SCIENCE AND PRACTICE OF CHEESE-MAKING 



evident errors of analysis, which are readily appar- 

 ent on careful examination. More recent work, 

 however, claims that some organisms can change 

 casein into fatty acids, while this is especially 

 denied by another investigator. So far as we now 

 know, the matter appears to be one mainly of 

 academic interest, since the change must be insig- 

 nificant in amount, if it occurs at all. In all of 

 our extended work with cheese, we have found no 

 evidence of an increase of fat at the expense of 

 proteins. And no one has yet reported an accumu- 

 lation of fat in a separator skim-milk cheese during 

 the ripening process, where the conditions surely 

 furnish enough protein material for such a trans- 

 formation. 



There is, however, one interesting condition 

 under which some fat appears to be changed, and 

 that is in case of cheese cured at low temperatures, 

 when we should ordinarily least expect such 

 change. It has been observed that, in cheese cured 

 near the freezing point of water, small white specks 

 may appear. These have been noticed at both the 

 Wisconsin and New York experiment stations as 

 well as in Europe. They have been supposed by 

 some to be salts of the cheese crystallized out in 

 little white aggregations, due to the dryness of the 

 cheese and the low temperature. One investiga- 

 tor has reported the spots as due to the result of 

 bacterial action on the fat in cheese, some of which 

 was decomposed, the decomposed portions forming 

 the minute white spots. Recently some cheese 

 filled with these white specks has been examined 

 at the New York experiment station. The white 



