Chocolate Panning

17

Traditional chocolate panning is the process of instances, to allow part of the center to show
applying layers of chocolate coating to inclusions through. Once a sufficient chocolate shell has
in a rotating pan or drum until the desired coating been built up on the center, the pieces are pol-
thickness is reached and the coating has com- ished and glazed to give an attractive, shiny
pletely solidified. These coated centers are then appearance. The general cross-section of a
polished and sealed. Panned chocolate confec- chocolate-­panned confection is shown in
tions have the advantage of being glossy and Figure 17.1. The four layers put onto the center
more resistant to scuffing and melting than include pre-coating (optional), chocolate shell,
enrobed or molded pieces. Here, the phrase polish, and seal coating layers.
‘chocolate panning’ will be used, but various
forms of compound coatings can also be used
with the same equipment to achieve the same 17.1.1 Centers
approximate finished products.
Centers for chocolate panning come in a wide vari-
ety. They may be fruits (raisins, cranberries, etc.),
17.1 Panning Operations nuts (peanuts, almonds, cashews, etc.), sunflower
seeds, coffee beans, specialty centers (cereal
Although called chocolate panning, this process pieces, corn nuts, cookie dough, etc.) or candy.
applies to the coating of various centers with Typical candies that may be used include fondant,
either chocolate, compound or yogurt-based caramel, malted milk balls, and jelly candies.
coating. The procedures and important points are For consistent product quality and an efficient
essentially the same for all three materials. The operation, the following parameters should be
process of chocolate coating follows the same considered and controlled (where possible):
basic steps as sugar-based coatings (see Chapter
13). After application of a pre-coating (where • Size: Center pieces for chocolate panning may
necessary), multiple layers of chocolate are built be as small as a few millimeters (e.g., sun-
up by sequential addition of liquid chocolate fol- flower seeds) to as large as a couple centime-
lowed by adequate time for solidification. While ters (malted milk balls). Smaller pieces tend to
composition may vary somewhat, two parts choc- be a little more problematic to coat well, par-
olate to one part center is typical for panned ticularly in terms of tumbling action. Probably
pieces. Equal proportion of coating to centers is most important about size is that all the pieces
sometimes used to reduce cost and, in some in the pan are about the same size. Having

© Springer International Publishing AG 2018 501

R.W. Hartel et al., Confectionery Science and Technology, DOI 10.1007/978-3-319-61742-8_17
502 17 Chocolate Panning

Chocolate/Compound notoriously difficult to pan; pre-coating these

Coating (3) centers is critical to getting uniform coverage.
• Surface irregularities: Chocolate coating
works best on smooth centers, but this is not
Polish (4) Pre-Coat (2) always possible. Surface irregularities are nat-
(optional)
ural in certain products (e.g., raisins, almonds,
coffee/espresso beans, etc.) and must be filled
in completely to produce a high quality piece.
Seal Coat (5) Center Mass (1) • Temperature: To ensure proper setting of the
chocolate or coating, the centers should be
Figure 17.1 Cross-section of typical chocolate-panned neither too hot nor too cold. Typically, tem-
candy
peratures between 15 and 25 °C are best.
Warmer temperatures do not allow rapid
consistent sized inclusions makes it easier to solidification of chocolate, whereas colder
maintain individual panned pieces rather than temperatures may cause undesired solidifica-
doubles and clusters. It also allows for uni- tion of chocolate into the wrong crystal poly-
form coating on all pieces. Also, particle seg- morphic form. Centers should generally be
regation within the pan may occur if there are tempered to the panning room temperature.
different sized centers, especially in tradi- • Minimal free moisture or fat: Migration of either
tional rotating pans. water or fat into the coating can cause shelf life
• Firm texture: Firmer centers make the panning issues. Moisture is particularly problematic
operation more efficient. When panning with since chocolate does not stick very well to a wet
soft centers, flexing may occur and the choco- surface, but even liquid oil (e.g., nut oils) can
late shell will break away. This is often seen in cause adherence problems. These problems are
raisins that are high in moisture or damaged minimized by using a pre-­coating layer.
during the cleaning process. Having a smaller • Dust. Centers should be as free of dust parti-
bed depth in the pan or pre-coating can help cles as possible. Dust and free powder (often
alleviate some of the flexing issues when pan- from precoating) should be minimized to pre-
ning soft centers. vent an increase in the coating viscosity. This
• Density: Center pieces for chocolate panning may also lead to an uneven coating shell and
vary widely in density, from quite low (e.g., small, coated balls of powder that will become
malted milk balls) to very high (e.g., almonds). waste product.
Lighter pieces may result in more problems,
particularly if tumbling action is not uniform. The ideal center for coating with chocolate
Centers should have uniform density to avoid would meet all of the above requirements.
segregation during tumbling. Unfortunately, most centers for coating with choc-
• Round: Centers should be as round as possible olate do not meet all the requirements. In general,
and have minimal flat sides or points. Round the easiest centers to chocolate pan include malted
centers allow for a uniform spreading of choc- milk balls, caramel balls and round-tipped
olate into a thin layer, uniformly coating the almonds, with the most difficult being sunflower
entire piece. It is often difficult to pan centers seeds, espresso beans and cashews.
that have flat sides or points. Centers with flat
sides have a tendency to stick together and
become doubles. Panning products with 17.1.2 Chocolates and Coatings
pointed ends are often difficult to cover with
coating as seen in some almond pieces. This A wide range of coating materials can be found.
can be solved by using the correct combina- These include the three main types of chocolate
tion of chocolate temperature, viscosity and (dark, milk, white) and a variety of compound
cooling. Pieces with concave surfaces are coatings.
17.1 Panning Operations 503

17.1.2.1 Chocolate points and solidification rates. The confectioner

Standard of Identity chocolate (see Chapter 15) is can select coatings with specific fat composition
often the coating of choice for panned goods. The to enhance solidification rates and control coat-
claim of “real” chocolate on the label is generally ing hardness. A second advantage is the possibil-
a good marketing point. The choice of dark, milk ity of adding colors and flavors. However, one of
or white chocolate is governed by consumer the usual advantages of compound coatings over
demands. Many commercial panned products are chocolate, namely that tempering is not needed,
made with milk chocolate, primarily based on con- does not apply in panning since chocolate can be
sumer demand. However, dark and white choco- applied untempered with no negative effects.
late panned goods are also widely available. Similar factors as discussed above influence
Choice of chocolate for use in panned goods is choice of coating for panned goods. Quality, con-
often based on several factors (Copping 1996). sumer demand and cost are still primary choices,
These include the desired quality of the product, as is rate of solidification. Again, the confectioner
based on the target consumer, and at what cost. has a wide range of options from which to choose
Viscosity range is also critical (see below for to find the best coating for use in panned goods.
more details). An additional factor is rate of
solidification since that is the major determinant
in panning times. 17.1.3 Pre-coating
Typically, dark chocolate solidifies quite rap-
idly, but that depends on the nature of the fat Pre-coating needs for different centers depend on
phase since cocoa butters from different origins the nature of the surface to be coated with choco-
are known to solidify at different rates (Marty-­ late. Of particular concern are moisture (e.g.,
Terrade and Marangoni 2012). Malaysian cocoa fruits) and incompatible oils (e.g., nuts), which
butter typically crystallizes more quickly into a must not be allowed to come in direct contact
harder chocolate than Brazilian cocoa butter, with the chocolate coating. If such products are
which takes longer to set and gives a softer coat- not pre-coated, the candy maker runs the risk of
ing. West African cocoa butter falls between having bloomed product as both moisture and
these two, but is generally soft (Copping 1996). nut oils can migrate into the shell coating and
If milk fat is used in the dark chocolate, the lead to bloom.
rate of solidification is reduced (Metin and Hartel Pre-coating of centers for chocolate panning,
2012) and the panned layer is softer. Of course, as with sugar panning (see Section 13.2.2), typi-
milk chocolate contains milk fat, so it also has a cally calls for application of a gum or starch
slower rate of crystallization. White chocolate solution followed by dry powder addition to seal
often contains a high level of milk fat and solidi- the center. Regardless of whether the pre-coat is
fies at a slower rate. In fact, white chocolate is intended to protect against moisture or oil
generally quite soft and may be harder to work migration, the solution component is typically
with than dark or milk chocolate. gum arabic or modified starch. These provide
decent barrier properties against both moisture
17.1.2.2 Compound Coatings and oil. The pre-coat solution must be at the
Numerous choices are available if Standard of appropriate viscosity to give good coverage of
Identity chocolate is not needed. Compound the center. Typically, solutions of 40–50% dis-
coatings (see Chapter 16) come in a wide range solved solids content are used. Several layers of
of flavors, types and formats. In addition to the coating solution are applied to the centers tum-
standard dark, milk and white coatings, other bling in the pan, with dry powder addition
choices include yogurt or carob-based coatings. between each solution application. Dry powders
Several advantages arise from using com- added may include starch, sugar or cocoa pow-
pound coating for panned goods over chocolate-­ der. After the pre-coat has been applied and
based coatings. First, greater control over the fat allowed to dry, the chocolate coating application
phase is possible, with a wider range of melting can begin.
504 17 Chocolate Panning

17.1.4 Chocolate Coating Application ingredient losses. The main parameters that affect
chocolate viscosity are temperature, fat content,
To ensure good coating and solidification of the emulsifier type and content, moisture content and
chocolate shell, the temperature and relative particle size of the chocolate or coating. These
humidity (RH) of the air applied into the pan must be controlled to give the desired viscosity
must be controlled to insure consistent success- for proper chocolate panning. See Chapter 15 for
ful panning. The exact air temperature and RH more details on the effects of these parameters on
will be dependent on the coating, centers and chocolate viscosity.
equipment, but generally range from 7 to 15.5 °C Typical viscosity values for chocolates and
(45–60 °F) and 35–50% RH. It is essential that coatings used depend on the centers being
there is no condensation of moisture from the air panned, equipment used, and air and room tem-
to the product. peratures/relative humidity. However, target val-
Melted chocolate or coating is applied at a ues are about 70 Poise (7,000 cP), with a range
temperature that depends on the application from 50 to 90 Poise (5,000–9,000 cP; or approxi-
method. For chocolate, hand ladling is applied at mately 35–45 Brookfield reading using the NCA
32–35 °C (90–95 °F), whereas ≈40.5 °C (105 °F) viscosity method; Copping 1996). As noted
and ≈43 °C (110 °F) are used for drip and spray above, chocolate with a yield stress on the lower
nozzle applications, respectively. Compound side is preferred for panning work to ensure
coatings are usually applied slightly warmer (as proper spreading of each application onto the
high as 46 °C/115 °F) to achieve a smooth finish. center.
Chocolate need not be tempered prior to applica- Chocolate may be applied by either hand
tion in panning since the tumbling process pro- ladling, drip feeding or spray nozzle, depending
motes formation of stable cocoa butter to some extent on the size of the candy facility.
polymorphs (see Section 15.5.5) and bloom is Typically, smaller facilities tend to use hand
usually not a problem. When tempered chocolate application and larger facilities favor drip feed-
is used, it will usually set too fast, resulting in an ing or spraying. Hand ladling involves applica-
uneven, rough coat and excessive adherence to tion of the proper dose of chocolate along (front
the sides of the pan. to back) the base near the top of the tumbling
A critical parameter to control in chocolate mass in the pan. In drip feeding, the chocolate is
coating, as in sugar coating, is the viscosity of the pumped through pipes to nozzles just above the
coating material. Viscosity of chocolate or coat- bed of tumbling centers in the pan, where the
ing must be of the right fluidity to provide ade- chocolate is allowed to drip onto the centers.
quate and complete coverage of the pieces. Spray feeding requires pumping the chocolate
Chocolate is a non-Newtonian fluid and there are to a spray nozzle where the liquid coating is
two parameters, yield stress and plastic viscosity, atomized to coat the centers. The spray nozzle is
that govern flow and coating ability (see Chapter mounted above the tumbling centers in the pan
15 for more details). In panning, both parameters with the chocolate spray aimed at the tumbling
are important, although the yield value, or the pieces. The advantage of the spray nozzle is that
force required to initiate flow in the chocolate, is it greatly reduces the tendency to form doubles
critical to the thickness of the shell being applied (or clumping); however, care is needed to ensure
(Aebi 2009). Viscosity must not be too low or the that the chocolate does not cool in the nozzle to
centers will not tumble well in the pan nor will plug up the lines. Further, the spray pattern must
sharp edges (on almonds for example) be ade- be controlled to achieve even coating.
quately covered. Conversely viscosity must also Regardless of the method of chocolate applica-
not be too high or inconsistent coverage of the tion, but especially in spray or drip feeding,
centers will occur. Furthermore, application of proper temperature control of the coating is crit-
high viscosity chocolate will cause excessive ical to good panning (adequate coverage with-
coating on the inside of the pan, resulting in out excessive clumping).
17.2 Pan Types 505

To build the chocolate shell in panning, sequen- pan to allow frictional heat to melt the rough
tial doses of chocolate are applied to the tumbling spots. Furthermore, release of compressed gases
centers with each liquid application followed by a requires that safety and environmental codes be
period of cooling and solidification. The amount satisfied. Condensation can also occur when
of coating used in each application dose must be using this method, which will result in the shell
high enough to ensure good surface coverage to soften.
without being too large to cause excessive clump- Often, a smoothing step is used to ensure an
ing of the centers. Groves (1992) suggests starting even coating with a smooth surface. Here, the
with 2.5 kg (5–6 lb) of chocolate per 45.5 kg (100 pan is tumbled without air flow to allow any
lb) of centers, increasing to 4 kg (8–9 lb) per irregular chocolate surface structures to become
45.5 kg (100 lb) of centers as the shells builds and smoothed out.
surface area increases. These numbers must be Once the desired chocolate shell has been
modified slightly for different initial surface areas applied, the candies are often held in pans to
of the centers. After application of the liquid choc- allow for sufficient solidification time to provide
olate and sufficient coverage of the centers, cool- a good base for finishing. When ready, the can-
ing air is blown into the pan to promote dies are returned to the pan for polishing and
solidification. Spray systems generally have air glazing. Some of the large automated panning
blowing at the same time, and the chocolate spray systems have eliminated this solidification step.
is constantly on throughout the run.
As mentioned earlier, air conditions are
important to making high-quality chocolate 17.2 Pan Types
panned products. Room air should be cool (15.5–
18.4 °C; 60–65 °F) and reasonably dry (40–55% There are three basic systems for panning: con-
RH). Cooling air directed into the pan is gener- ventional or traditional revolving pans, belt coat-
ally cooler (7–15.5 °C; 45–60 °F) and drier (<35– ers and automated pans. All three methods of
50% RH) to ensure proper solidification without panning follow the same basic procedures and
the risk of moisture condensation. The air should processes of building a coating layer, polishing
be filtered to insure products are safe from micro- and sealing coating.
biological or other contaminants. Air velocity Conventional revolving pans (Figure 17.2)
must also be controlled since cooling require- come in various sizes and shapes but most com-
ments may be different depending on the stage of mon are the round pans and tulip pans. These
panning. Generally, a recommended air flow rate pans are usually at an angle (about 25°),
is 500–850 m3 per hour (300–500 ft3 per minute). ­sometimes with a variable pan rotation speed.
Chocolate panning under adverse conditions The pan rotational speed depends on the pan size
(warm, humid air) generally results in poor qual- and design, the type of centers that are being
ity products with low production output. panned and whether the process is building the
Typically, from 5 to 10 min is needed to chocolate layer or the final polishing stage.
ensure adequate solidification of one layer prior Traditional panning rooms have one set of pans
to application of the next dose of chocolate. for building the coating layer (engrossing) and
Coating materials should be selected with solidi- another set of pans (ribbed) for polishing and
fication rate in mind. The application and solidi- final seal coating. While conventional pans are
fication cycle continues until the desired shell very versatile and economical, they require more
layer is built up on the piece, with panning times operator skill and production is more limited
anywhere from 0.75 to 2 h. More rapid solidifica- (160–225 kg; 350–500 lb) than panning with a
tion can be induced by use of a vaporizing refrig- belt or automated drum pans.
erant like carbon dioxide (dry ice) or nitrogen, Belt coaters are widely used for chocolate
although this leads to a rough surface that must panning (Figure 17.3). Belt coaters have an end-
be smoothed out by tumbling the pieces in the less belt that forms a ‘pocket’ for the centers to be
506 17 Chocolate Panning

Figure 17.2 Typical

tulip-shaped revolving
pan (Courtesy of Latini)

Figure 17.3 Belt

coater for chocolate
panning (Courtesy of
Schebler)

coated. The movement of the belt causes the ferred to rotating pans or another belt coater for
product to fall back upon itself to cause the rota- polishing and sealing. Production volumes are
tional effect to build up the chocolate layer as the usually higher than rotating pans, but lower than
chocolate is applied. After engrossing, the belt is automated pans. Ranges from 225 to 450 kg
reversed to unload the product. It is then trans- (500–1000 lb) are common. These pans are well
17.3 Finishing 507

Figure 17.4 Chocolate

coating drum (Courtesy
of Dumoulin)

Figure 17.5 Inside of a

drum coater showing
tumbling pieces. Spray
nozzles (not operating)
can be seen at upper left,
above the candy pieces
(Courtesy of Dumoulin)

suited for the midsized manufacturer that wants for engrossing and one for polishing and sealing,
economical, consistent product with less operator it is possible to do all these operations in one
artisanal skill required. Polishing results with a drum. Typical batch sizes for automated pans
belt coater may be more challenging than with a range from 450 to 2270 kg (1000–5000 lb).
revolving pan. While all three methods can produce high
Automated pans have a large rotating drum quality candy, product quality will always be
with controlled conditions that can supply the dependent upon the consistency of the starting
needed powders, coating, polishing, conditioned materials, operating conditions, and operator skill.
air and sealing agents in a precise manner. They
are self-contained units with spray bars, nozzles,
feeders, baffles and vents to accomplish this 17.3 Finishing
(Figure 17.4). Figure 17.5 provides a glimpse of
product tumbling in a drum coater. With their Once the center has been coated, various finish-
large size, it is possible to have a smaller bed ing options may be chosen. The standard finish is
depth that will prevent crushing of centers that to polish and glaze, but other options exist. These
are fragile or flexible such as seeds or raisins. include finishing with powdered sugar, cocoa, a
While many of the automated pans use one drum hard sugar-shell, spices, or speckling.
508 17 Chocolate Panning

17.3.1 Polishing seldom used in present panning operations, the

use of waxes (beeswax or carnauba) can be used
Polishing of panned products creates a glossy as an alternative to confectioners glaze.
appearance for customer appeal. A glossy appear-
ance cannot occur unless the panned centers are
smooth, firm and free of dust. For batch revolving 17.3.3 Hard Sugar Shell
pans the centers are put into a ribbed pan so that
the pieces can be picked up by the sides of the Some chocolate panned items will be finished
pan to provide adequate tumbling action. This with a sugar shell instead of the typical high gloss
tumbling action with a polishing agent causes a appearance. This procedure will make the fin-
shiny gloss to the finished product. Polishing ished product somewhat heat stable and is often
agents are usually water based and include gums, seen on seasonal products such as Robins egg
starches or dextrins. While they can be made in-­ malted milk balls. Chocolate-coated nuts and
house, they can also be purchased premade with seeds often have a hard panned sugar shell
a blend that contains the desired properties. The applied to the outside (Chapter 13). As with any
dosage for polishing materials depends on its for- sugar panned chocolate product, panning condi-
mulation, the size of the centers and equipment tions require temperatures below the melting
used. Typical starting point is 0.20–0.50% pol- point of the chocolate layer. It is common to
ishing solution that is usually about 60% solids. apply polish and glaze layers to the hard panned
The polishing solution is applied to the centers sugar shell in the same manner described above,
and the pan is rotated to evenly spread the solu- but using a wax-based polish rather than a water-­
tion. Conditioned air is then applied to dry the based polish.
solution and develop a gloss while tumbling. Two
to three doses are usually required to develop a
sufficient sheen. 17.3.4 Powdered Finishes

While the majority of panned items are polished

17.3.2 Glaze Coat and seal coated for a glossy appearance, some are
made with a ‘matte’ finish. After the engrossing
Once an acceptable gloss has been obtained it steps are completed and the product has a smooth
must be protected. The most common method to surface, a powder such as cocoa or sugar is intro-
maintain gloss, provide a moisture barrier and to duced into the rotating pan. These powders,
a small degree some heat resistance to the coating sprinkled onto the last layer of chocolate applica-
is to use confectioners glaze. Confectioners glaze tion, are incorporated into the coating layer by
is an edible shellac dissolved in alcohol that may the tumbling forces to give the desired finished
also contain other minor functional ingredients. appearance.
The traditional method is to apply approxi-
mately 0.15–0.20% seal coat to the centers and
rotate the pan until they are coated. Rotation is 17.4 Storage and Handling
stopped and conditioned air is applied to dry the
glaze coat. The pans are occasionally turned to After the panning process is completed the cen-
prevent massive clumping. When dry, the rota- ters are often stored in pans or totes before pack-
tion of the pan resumes for a short time to remove aging. They are typically stored in an area with a
“kiss-marks”. The addition of other ingredients temperature range of 15.5–20 °C (60–68 °F) with
to the confectioners glaze, such as oils or mono a RH of 40–50%. Higher RH will result in the
and diglycerides, will allow for continuous rota- pieces sticking together while a lower RH can
tion of the pans to seal coat the centers. While result in the cracking of the seal coat due to dry-
17.5 Trouble Shooting 509

ing. Gentle handling techniques should be ter ratio. For centers that are not uniform in shape
employed until the panned confections are pack- or have cracks and crevices, a good pre-coating
aged where they will have protection from the layer application can help smooth out the surface
environment. onto which the chocolate coating is applied.
Like other chocolate items, they should be Increasing the amount of chocolate coating
stored in sealed packaging with good moisture applied or reducing coating viscosity might also
and oxygen barriers. Storage conditions should help spread the coating uniformly before it
be odor free with typical temperatures of 18 ± solidifies.
2 °C (64 ± 4 °F) with a RH of 45 ± 5%. While Exposed surfaces may also be caused by sharp
chocolate-panned items are more resistant to heat edges, such as the point edge of an almond. If
than molded and enrobed chocolate pieces, rounded-tip almonds cannot be used, alternatives
extreme heat exposure will cause fat bloom and include ensuring there is good pre-coat for the
product deformation. chocolate coating to adhere to and that the vis-
cosity of the coating is properly set. If the choco-
late coating is too warm, it will not adhere to that
17.5 Trouble Shooting sharp point. Making sure that the first applied
chocolate layers are well set will also help.
Consumers expect a consistent high quality prod-
uct. As in any operation, there are challenges that
can result in unacceptable product. The following 17.5.3 Bumpy/Rough Surface
are some common defects found with chocolate
panning and suggested solutions needed to cor- When the chocolate coating layer is rough or
rect the problems (Copping 1996). bumpy, several factors may be considered. For
one, the chocolate coating could be too thick so
that it does not spread uniformly before it begins
17.5.1 Incomplete Coverage to set. Raising the temperature of the chocolate
coating will help reduce viscosity and smooth out
If the pieces are not completely coated with choc- the applied layer. Air that is too cold could also
olate coating, leaving bare spots, it is likely that cause a rough surface by causing too rapid solidi-
the coating was either applied at too low a ratio fication of the chocolate coating. Rough surfaces
(coating to center ratio) for the surface area of may be smoothed out by turning off the cold air
pieces or it was not able to adequately spread and allowing the pieces to tumble. The heat
before it cooled and set. If the proper level of ­generated during tumbling will soften the coat-
chocolate coating was added, perhaps the viscos- ing, allowing it to smooth out.
ity of the coating was too high and/or its tempera-
ture was too low. Increasing temperature might
eliminate the problem. Air flow and temperature 17.5.4 C
 hocolate Not Sticking/
may also be the problem, causing the chocolate Peeling
coating to solidify too rapidly, before it could
spread evenly. A pan that is rotating too slowly Probably the main cause of a chocolate coating
could also contribute to this problem. either not sticking or peeling off the center is the
lack of a pre-coat. When a chocolate coating is
applied on top of a moist surface (as in some
17.5.2 Poor Coverage fruit centers), it will not adhere to the surface. A
good layer of pre-coating to bridge between oil
Pieces that are not evenly covered could be and water should allow the first layer of choco-
caused by uneven centers or a low coating to cen- late coating to adhere and help the problem.
510 17 Chocolate Panning

Chocolate coating not sticking to the center can 17.5.7 Bloomed Pieces
also be caused by too thin a viscosity. Possible
causes of this might include coating temperature Although bloom on panned chocolate pieces is
too high, air temperatures too high or centers rare, there are some instances when bloom can
being too warm. Other potential causes include appear on panned goods. This is usually related to
pan speed too high, centers too soft, or a heavy incompatible fat systems; for example, a nut oil
load in the pan. migrating into a chocolate shell. To prevent this, a
good pre-coat layer is needed to help limit migra-
tion. Another possible source of fat bloom is stor-
17.5.5 Doubles age or transportation conditions that are too warm.
Although numerous problems can arise in
A common problem is that pieces stick together chocolate coating, it is actually considered the
to form doubles or even clusters. Not allowing easiest panning method to learn. In general,
the chocolate to solidify properly before adding chocolate coatings are relatively forgiving and
more is the most likely reason. Another com- problems more easily rectified.
mon cause of doubles is that the chocolate coat-
ing is added too fast so that it does not spread Acknowledgment Thanks to Michelle Frame (Victus
into a uniformly thin layer. The proper coating Ars) for providing input on this chapter.
to center ratio is required for proper pan opera-
tion. Doubles may also be caused by a chocolate
coating that is too thick. Reducing viscosity, for References
example by raising the coating temperature, or
Aebi M. Chocolate panning. In: Beckett ST, editor.
switching to a spray system can both potentially Industrial chocolate manufacture and use. 4th ed.
help this problem. Pieces sticking together may Oxford: Wiley-Blackwell; 2009. p. 374–5.
also be caused by a pan that is turning too Copping T. Basics of chocolate panning. In: Proceedings
slowly. Check that proper pan rotational speed of 50th PMCA production conference, Hershey; 1996.
p. 115–23.
is being used. Groves R. Chocolate panning. In: Proceedings of the
46th PMCA production conference, Hershey; 1992.
p. 135–40.
17.5.6 Crushed Centers Marty-Terrade S, Marangoni AG. Impact of cocoa butter
origin on crystal behavior. In: Garti N, Widlak N, edi-
tors. Cocoa butter and related compounds. Champaign:
Centers that break during application of a choco- AOCS Press; 2012. p. 245–74.
late coating are generally caused by having too Metin S, Hartel RW. Milk fat and cocoa butter. In: Garti
heavy a load in the pan for the sensitivity of the N, Widlak N, editors. Cocoa butter and related com-
pounds. Champaign: AOCS Press; 2012. p. 365–92.
center. Reducing pan load should help.