MJBizMag July 2021 - 58

SCALE
Thread
Soft Ball
Firm Ball
Hard Ball
Soft Crack
Hard Crack
HOW IT
SUITS YOU
ENERGY NEEDED FOR CANDY PRODUCTION
Stage
Degrees
225 F
237 F
245 F
259 F
280 F
305 F
% Solids
80%
85%
87%
92%
95%
99%
kW, 1 hour
0.42
0.59
0.66
0.83
0.96
1.12
kW, 30 minutes kW, 15 minutes
0.84
1.18
1.32
1.66
1.92
2.24
1.68
2.36
2.64
3.32
3.84
4.48
The table shows calculations to cook 10 pounds of a general confectionery mixture of corn syrup, sugar and water at room temperature of 70 degrees
Fahrenheit and a total initial solid of 75%. The table illustrates how many kW it takes to cook that solution to various " candy " stages. These calculations do
not consider the amount of energy it requires to heat the pot or vessel you are using. This also assumes no heat is lost to surroundings and 100% efficiency.
* Will there be a change in water
content from start to finish-and, if
so, how much?
heating capacity. An 80-pounds-of-steam
boiler would have a similar cooking
capacity as a single stock pot gas burner.
* Ideally, how much time do you
require for a cook cycle?
SIZING EQUIPMENT CHOICES
Electric Cooking: Most people use
electric equipment-whether it's a
hot plate or induction burner. In each
of these cases, the kilowatts (kW) at
a given voltage is usually stated on a
specification sheet. Both are important!
If the voltage of a facility is lower than
the electric device's kW rating voltage,
the total available kW will be less-and
you must take this difference into account.
To learn your facility's voltage, inquire
with the maintenance department
or take a voltage meter and measure it at
a receptacle.
If equipment is rated at 240 volts single
phase and is supplied with less than 240
volts, the kW will be derated. At 230 volts,
the output is 92%; at 220 volts, the output
is 84%, etc.
If you have an electric cooker rated at
10 kW and 240 volts single phase that
was operating on 208 volts single phase,
the available kW would be 7.5. From the
table, cooking a 30-pound batch to hard
ball stage in 15 minutes requires 9.96 kW
(3.32 kW x 3 because the batch is three
times larger than the amount listed in
the table).
58 MJBizMagazine | July 2021
John Vessa and Kelly Froehlich
Cooking it to the same stage in 30
minutes requires 4.98 kW (1.66 kW x 3).
With 7.5 kW available at 100% efficiency,
you would expect the cook time to be no
less than 22.5 minutes.
Gas Flame Cooking: The output of a
commercial single stock pot-sized gas
cooker can be as high as 80,000 Btu per
hour. That rate equates to about 23.5 kW.
With the control turned down to about
33%, this cooker will generate the same
7.5 kW as the electric cooker above.
With the flame control turned to the
maximum, you would expect those cook
times to be about one-third of those in
the table. That would be 20 minutes,
10 minutes and 5 minutes to achieve the
same energy transfer.
Steam Cooking: Steam boilers,
whether electric- or gas-powered, are
generally rated in pounds of steam per
hour. A good rule of thumb is 1,000 Btu
per pound of steam. A boiler would need
to produce at least 26 pounds of steam per
hour to have the equivalent of 7.5 kW
FINAL CONSIDERATIONS
This story assumes 100% efficiency,
which is rare. Heat loss from hot
surfaces is usually not a large part of the
calculation, but it should be considered
because it may reach as high as 5% of the
total available kW. Generally, oversizing
by 25% takes care of any losses not
specifically accounted for.
The most common unknown is
the product itself. As candy masses
cook, they become more viscous and
may not transfer heat very well. In
this case, the surface temperature of
the cooker must be reduced to avoid
burning. Increasing the cooking
surface would help, but whether that
is practical will depend on the size of
your kitchen.
John Vessa is a senior application engineer
at CandyWorx, a Spec Engineering Brand.
Kelly Froehlich is the marketing content
manager at Spec Engineering. Since 1979,
Spec Engineering, a Gray company, has
been a single source for system design and
process equipment integration. CandyWorx
is a custom equipment and solutions
provider for the confectionery, chocolate
and cannabis industries. Learn more at
spec.engineering and candy-worx.com.

http://www.candy-worx.com

MJBizMag July 2021

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