Useful Rules and Tests: 38538 
To Sranparpi1zE CREAM AND Mixx (Pearson) 
When cream is being sent to the city trade or used for certain other 
purposes, it is often desired to have it contain a certain percentage of 
fat and the same each day. It is difficult to adjust a separator to skim 
cream always of the same richness and it has become a more or less 
common practice to skim a heavy cream and “‘standarize’”’ it. This is 
done by mixing with it enough of the skimmed milk that has just been 
removed, or whole milk or thinner cream, to reduce the fat content 
to the proper point. 
The following is an easy and accurate way to determine the quan- 
tity of skimmed milk, milk, or thin cream that must be added to a 
rich cream to produce a cream of required richness or fat content: 
Draw a rectangle and write at the two left-hand corners the per- 
centages of fat in the fluids to be mixed, and in the center, place the 
required percentage. At the upper right-hand corner put the number 
which represents the difference between the two numbers standing 
in line with it, 4. e., the number in the center and the one at the lower 
left-hand corner. At the lower right-hand corner put the number that 
represents the difference between the two numbers in line with it. Now 
let the upper right-hand number refer to the upper left and the lower 
right-hand to the lower left, then the two right-hand numbers show the 
relative quantities of the fluids represented at the left-hand corners 
that must be combined to give a fluid of the desired standard which 
is represented in the center. 
For example, suppose we have cream testing 39 per cent fat, and we 
wish to standardize this to a 30 per cent cream by the use of milk 
testing, 5 per cent fat. Following the directions we have this diagram— 
39 | 25 
30 - 
5 : 9 
which shows at once that 39 per cent cream and 5 per cent milk must 
be combined in the proportion of 25 to 9 in order to produce 30 per 
cent cream. If we wish to use.50 pounds of 39 per cent cream, then 18 
pounds of 5 per cent milk must be added, as is shown by this proportion. 
25:9 ::50:18 
WwW 
