156 Evaporated Mi.K—MoJonNIkER CONTROLLER 
export purposes the viscosity should be higher, around 200 
degrees. : 
A 150 degrees viscosity of evaporated milk immediately 
after sterilization is equivalent to a viscosity of from about 
80 degrees to 100 degrees by the time the milk is ready to leave 
the shipping department, and this represents about the correct 
viscosity for the summer months. For the winter months the 
viscosity should not exceed about 80 degrees retardation. E.x- 
cessive viscosity invites the “feathering” or curdling of the evap- 
orated milk when used in hot coffee or when diluted with hot 
water. 
Adding Sodium Bicarbonate to Batch of Evaporated Milk.— 
As soon as the controller and viscosimeter tests are completed, 
the batch of evaporated milk is ready to be filled into the tin 
cans. In case it is necessary to add sodium bicarbonate, the 
following procedure is recommended: 
For convenience sake we will assume that can No. 2 in 
the test showed the correct viscosity, as represented by a retar- 
dation of 150 degrees. To this can had been added sodium 
bicarbonate on the basis of two ounces per 1,000 pounds of milk. 
The entire batch of milk containing 24,000 pounds evaporated 
24,000 « 2 
milk, hence —~—~.——-—= 48 ounces of solid sodium bicarbonate 
1,000 
are carefully weighed out. This amount of bicarbonate is con- 
veniently placed into a 10-gallon milk can, a small amount of 
water is added and preferably also a small amount of evapo- 
rated milk. This mixture is then heated to a vigorous boil, 
which can easily be done by means of the steam hose. ‘The 
boiling should be continued until the greater part of the gas 
generated has been expelled. 
The hot mixture is now added to the entire batch of evapo- 
rated milk in the holding tank. It should be added slowly and 
the evaporated milk should be kept thoroughly agitated, not 
only while the bicarbonate is added but for from 10 to 20 min- 
utes after its addition. 
Adjusting Sterilizing Process to Different Sizes of Cans.— 
As stated elsewhere in this chapter, different sizes of cans 
require different sterilizing formulas to insure complete steriliza- 
tion, and a similar effect has been found also with reference to 
