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184662
DUKE Model 957R Soft Serve Freezer
temperature variation of only 1.5°F (1°C) on
a product temperature of 18°F (-8°C). The
control panel dial thermometer should show
a measurement of 5° to 15°F (-15 to -9°C)
when product is being dispensed at 18°F (-
8°C). Although this dial thermometer is not
accurate for measuring product tempera-
ture, it is wise to accustom the operators to
observe the dial thermometer for its normal
operating reading.
10.4 Overrun
H. C. Duke and Son, Inc. can provide a
scale (part #158049) that is graduated in
overrun percentage.
Section 10.7 is an overrun chart which
shows the net weight of one measure pint of
frozen Dairy Queen
®
product in grams,
ounces, and their corresponding percentage
of overrun.
NOTE: Each person who operates the
freezer should know what overrun
is, and how to calculate it.
The product temperature should be mea-
sured by a calibrated thermometer. If you
suspect that the thermometer is out of
calibration, test it by filling a cup with ice
and water and inserting the thermometer
into it. After a few minutes, the thermometer
should read exactly 32°F (0°C).
The freezer should maintain a product
10.3 Product Temperature
“Weight of liquid mix minus weight of frozen
product. Divide the difference by the frozen
weight.”
Example:
Weight of one pint of mix =18 oz.
Weight of one pint frozen product =12 oz.
Difference 6 oz.
6.0 oz. divided by 12 oz. = .5
.5 x 100 = 50% overrun
As mix is being frozen in the freezing
cylinder, air is incorporated into the mix to
increase its volume as well as the taste and
appeal of the finished product. The increase
in volume is called
overrun
. Forty five
percent overrun means a volume increase of
45%—10 gallons of liquid mix has become
14.5 gallons of finished product.
Controlled overrun is important in maintain-
ing consistency in product quality. Too
much overrun (air) results in a light, fluffy
product lacking the cold, refreshing appeal of
a quality product. Too little overrun results in
a grainy, heavy product.
To correctly measure the overrun,
1. Take a pint container and adjust your
scale to zero
with
the container on the
scale.
2. Fill the container with liquid mix, even with
the top of the container and record the
weight.
3. Then fill the container with frozen product,
leaving no voids or air spaces in the
container. Strike off the excess product so
it is even with the top of the container and
weigh it.
4. Use the following formula to figure overrun
percentage: