154 EVAPORATED Mii.K—MojJoNNiER CONTROLLER 
The viscosity test therefore furnishes a measure of the 
resistance of any given batch of évaporated milk toward steril- 
izing heat. But in order to enable the operator to correctly 
interpret the results of this test and to correctly govern his 
method of handling the evaporated milk according to these 
findings, he should have a clear understanding of the correlation 
of the several factors that influence this resistance to heat and 
that affect the viscosity. 
\Vith reference to the 
viscosity) in which these several factors influence the viscosity 
and the tendency to curdle the evaporated milk, the following 
direction (increase or decrease of 
general facts should be known: 
Factors that “1. high per cent acid in milk 
increase the vis- 2. low stability of proteins 
cosity and the 3. high concentration of evaporated milk 
tendency to curdle) 4. high sterilizing temperature 
the milk 5. long exposure to sterilizing temperature 
6. high pressure in homogenizer 
(1. low acidity in milk 
2. great stability of proteins 
Factors that 3. low concentration of evaporated milk 
decrease the vis- | 4. low sterilizing temperature 
cosity and the 5. short exposure to sterilizing heat 
tendency to ee 6. high temperature in forewarmer 
| 7. extraneous water in evaporated milk 
S. low pressure in homogenizer 
GS, addition of bicarbonate of soda 
The exact quantitative relation of most of these factors to 
one another and to the viscosity of the evaporated milk has been 
experimentally determined by Mojonnier Bros. Co. for evapo- 
rated milk standardized to 7.8 per cent fat and 25.5 per cent 
total solids as follows: 
A 40 degree retardation or viscosity as determined by the 
Mojonnier viscosimeter corresponds to: 
1. One degree I. in sterilizing temperature at the holding 
point of 240 degrees F., when held for 15 minutes and with the 
same ‘“‘coming-up” 
Sample Cans.”’ 
time as given under “Sterilizing the Five 
This means that each degree F. above 240 de- 
