NEw York AGRICULTURAL EXPERIMENT STATION. 179 
3. METHOD FOR DISTINGUISHING WHOLE-MILK FROM SKIM-MILK 
CHEESE. 
Cheese made from normal milk rarely contains when green less 
than 32 per ct. of fat, but such cheese may contain only 30 per ct. 
of fat if an unusually large amount of moisture has been held in 
the cheese. The percentage of fat varies, of course, with the per- 
centage of moisture, and hence the percentage of fat in cheese 
may not always be a reliable guide as to whether the cheese is made 
from whole milk or skim-milk. The percentage of fat becomes a 
reliable guide if we eliminate the moisture, which is a quite variable 
constituent. In all of our work, it has been found that the cheese- 
solids (cheese minus water) contain over 50 per ct. of fat if the 
cheese is made from whole milk. The variation is from 50.39 to 
50.83 per ct., with an average of 53.56 per ct. The remainder of 
the cheese solids or solids-not-fat consists of nitrogen compounds, 
ash, etc. Our work was made the basis of the United States Gov- 
ernment standard for cheese, which requires that in whole-milk 
cheese 50 per ct. of the cheese-solids shall consist of fat. Cheese 
containing less fat is presumed to have been made from skimmed 
milk. 
Another relation can be used for distinguishing whole-milk from 
skim-milk cheese and that is the ratio of fat to nitrogen compounds. 
We have found that in no case in cheese made from normal milk 
is the proportion of fat to nitrogen compounds less than 1.27. The 
ratio varies from 1.27 to 1.60 and averages 1.42. It is safe to 
say that in cheese made from normal milk this ratio should not be 
less than 1.25. 
When, in the process of cheese-making, abnormally large amounts 
of fat are lost, the result may be the same as if the cheese were 
made from partially skimmed milk. Such cases are rare but it is 
easily possible that they may occur now and then. 
II]. THE CONDITIONS OF THE OPERATION OF CHEESE-MAKING 
INeRECASION =| Oe Vib DeANDIOUALILY. OF: CHEESE: 
Variation of conditions during the operation of cheese-making 
makes profound differences in the character of the resulting product. 
We have studied the effect of varying certain conditions of cheese- 
making upon the yield and quality of cheese and we will now 
briefly review the results of these experiments after giving a sum- 
mary of the various conditions which were found to be employed 
at different cheese factories. 
