LABORATORY CATALOGUE for milk analysis - Labochema

Determination of the fat content in homogenized milk according to Gerber’s method
Treated milk is homogenized to avoid creaming. This involves reducing the differentsized
fat globules to a nearly equal diameter of 1 to 2 micrometers. This considerably
decreases the separating effect of the centrifuging process. In order to completely
separate off the released fat, the specimen must be centrifuged for a longer period
of time.
Process steps 1 to 8 for the testing of non-homogenized milk are carried out and the
result is recorded.
Then, the butyrometer is once again heated to 65°C in a water bath for at least 5 minutes
and subsequently centrifuged again for 5 minutes. The result is read off in the
same way as before.
If the value obtained after the second centrifuging is more than 0.05 % higher than the
value after the first centrifuging, then the reheating and centrifuging is to be repeated
a maximum of two times.
However, if this value has increased by only 0.05 % or less with respect to the first
value, the highest test value applies.
Example:
• After the first centrifuging, the two values were read off at 3.55 % and 3.60 %.
• After the second centrifuging, the two values were 3.60 % and 3.65 %. The homogenised
milk fat content is stated to be 3.65 %.
• Should the difference still be greater than 0.05 % after the two last repetitions, i.e. after
the 3rd and 4th centrifuging, the results of this test are to be discarded.
Laboratory catalogue for milk analysis
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