92 April 2014 • The Manufacturing Confectioner

➤

Producing confections using multiple lay-ers of centers presents an opportunity

for the artisan confectioner to create uniqueproducts and an expanded product line,often while using formulas that are alreadyin an existing repertoire. The keys to suc-cess are in understanding the compatibilityof centers and inclusions with regard tomoisture and fat migration, and the pro-cessing techniques that are required for thevarious centers.

ADVANTAGES OF LAYERING CENTERS

By combining multiple centers within onepiece, the potential flavor profiles areexpanded and the flavor complexity isenhanced. Flavors may be classic combina-tions like an American pb&j , a Europeanblack forest or tiramisu, or flavors evokingother cultures such as Latin American dulcede leche or Asian sesame. Flavor combina-tions may also be more avant-garde, mod-ern and unexpected in a confection, like yuzuand black sesame, bacon and maple, or sun-dried tomato and olive oil. Whatever thegoal, exponentially more complex flavor pro-files can be expressed using multiple layersthan can be achieved using one center alone.

In addition to achieving interesting fla-

vor combinations, layering centers also per-mits greatly heightened textural variationswithin a piece. The possibilities for texturalcontrast are myriad, such as a crispy nuttylayer combined with a marshmallow or softnougat, a chewy caramel combined with arich, creamy ganache and nuts, or a crisplayer combined with a nearly fluid caramelcenter. The textural combinations are almostendless, and are limited only by one’s under-standing of the centers employed.

All of these wonderful flavor and tex-tural advantages can often be achieved usingformulas that are already in use in the oper-ation, but assembling them in combinationsrather than individually. This technique cre-ates an opportunity for a greatly expandedproduct line of unique, signature items usingexisting formulas.

The technique of layering centers can beapplied to either individual pieces or to arti-san chocolate bars. Many manufacturers doa brilliant job with layered chocolate bars,but there is no reason artisans should notcreate their own bars. In doing so, artisansmight do well to avoid mimicking the pop-ular mass-produced bars on the market, butmight better focus on making unique, nichebars that manufacturers would not produce

Layers of FlavorsThe keys to success in producing artisan confections with multiple centers are in understanding the compatibility of centers and inclusions.

Peter GrewelingThe Culinary Institute of America

Peter Greweling is aprofessor of bakingand pastry arts at theCulinary Institute ofAmerica.

because of their more narrowly focusedmarket appeal, or could not produce due tolimited shelf life or higher cost.

CHALLENGES OF LAYERING CENTERS

There are definite challenges accompany-ing the advantages of layered confectionsthat must be overcome to be successful.These challenges relate both to produc-tion techniques and to shelf life of the fin-ished product. The production issues arethe assembly technique and the logisticsof assembly, while the shelf-life concern isprimarily migration of fats and waterwithin a layered confection.

Moisture Migration

The first and arguably the most importantchallenge to understand when combiningcenters is moisture migration. Moisturemigration occurs when the free water froma center with higher water activitymigrates into a center with lower wateractivity. Over time, the water activity (Aw)in each of the centers will equalize, chang-ing the characteristics of both. In the exam-ple in Figure 1, moisture from the ganachemigrates into the lower-Aw caramel,destroying the quality of each.

Moisture migration causes loss of tex-tural contrast between layers; crisp cen-ters or inclusions can become soggy, andsoft centers or inclusions can becomefirmer. Moisture migrating into a non-crystalline center such as a caramel or tof-fee causes crystallization of the sugar, againresulting in totally altered mouthfeel andflavor from that which the centers origi-nally had. Moisture migration is the fastestway to a diminished shelf life in layeredconfections, and will very quickly result ina loss of quality of both centers and inclu-sions if it is not controlled.

There are several ways to avoid dam-age from moisture migration when usingmultiple layers within a single piece. Using

centers with a very similar Aw will preventmoisture migration and is a very practicalsolution. As an example, two layers of dif-ferent flavors of ganache combined willnot suffer from moisture migration. Cen-ters with similar Aw, however, are likelyto have little if any textural contrastbetween them, and so the opportunity forinteresting textures is diminished. Usingcenters, such as fat systems, that are notaffected by moisture migration is anotherway to avoid the problem. Fat systems suchas gianduja are virtually unaffected bymoisture migration, but using only fat sys-tems as centers severely limits variety. Theother technique to mitigate moisturemigration is to create moisture-resistantbarriers between components with dis-parate water activity. Any non-water- soluble material such as fat, wax and shel-lac is an effective barrier to moisturemigration, and commercial products forthis use are available. The simplest solu-tion for most artisans is to apply a layer offat such as cocoa butter between layerswith disparate Aw to prevent the move-ment of water and the subsequent loss ofquality within the confection.

Fat Migration

Like moisture migration, fat migrationwithin a layered piece can also lead todiminished quality. Fat migration occurswhen fat of a lower solid fat content, such

Moisture migrationis the fastest wayto a diminishedshelf life in layeredconfections, andwill very quicklyresult in a loss ofquality of bothcenters andinclusions if it isnot controlled.

The Manufacturing Confectioner • April 2014 93

➤

Moisture moves from the higher-ERH center intothe lower-ERH center until equilibrium is reached.Result: dry ganache and crystallized caramel.

Figure 1

Moisture Migration

as nut oil, migrates into fat of a higher solidfat content, such as cocoa butter. Ulti-mately, the fats blend until their solid fatcontent becomes equal. In Figure 2, the oilfrom a nut paste layer migrates into achocolate layer.

If left unchecked, fat migration also hasdeleterious effects on layered confections.Fat migration causes chocolate to bloomprematurely, in as little as a couple ofweeks with some nut paste centers. Fatbloom, while harmless, makes productsunsalable, and so fat migration can veryquickly destroy products. Bloom is not theonly malady brought on by fat migrationthough; as fats migrate and equalize, tex-tural contrast is lost. For instance, in apeanut butter center enrobed in chocolate,the chocolate will soften and the peanutbutter filling will become more firm, untileventually all textural contrast is lost. Fatmigration can also lower the melting pointof chocolate, resulting in easily damagedpieces. This is a particular concern withlauric fats such as coconut oil, which havea pronounced eutectic effect on cocoa but-ter, resulting in a greatly lowered meltingpoint of the chocolate. As fats migrate andequalize, the flavors within the componentsalso blend, resulting in a more uniform,less distinct and less interesting flavor expe-rience for our consumers.

Like moisture migration, fat migrationcan be avoided by using centers with very

similar fats within a piece. Again, though,they are unlikely to have the desirable tex-tural contrast of dissimilar fats. There aretimes that incompatible fats, such as oil innuts or lauric fats, when used with choco-late, provide flavor or textural effects thatgive the products unique characteristics,and therefore are vital to the success ofthe piece. Barriers to fat migration are aneffective method to prevent loss of qualitybetween incompatible fat components. Abarrier to fat migration must be an aque-ous solution such as gum arabic, starch orpectin. Again, several manufacturers makeproducts that are well suited to this sortof application.

Assembly Techniques

Matching the proper assembly technique tothe centers is another key to success whenmaking layered confections. Creating slabsof the layers, then cooling, cutting andenrobing is the most commonly employedmethod of assembly. Centers that aredeposited hot, such as soft caramels or jel-lies, must be assembled by slabbing. Cen-ters with good stand-up quality, that won’tflow and will hold their shape, such asganache and butter ganache, are well suitedto slabbing technique. The alternative toslabbing centers is to shell mould them.Shell-moulded centers must be depositedat much cooler temperatures, below 85°F,so as to not damage or melt the chocolateshell. An advantage of shell moulding isthe use of centers that are soft and couldnot be cut and enrobed; soft centers pro-vide textural contrast within a confection.Caramel filling (true caramel, not thestand-up soft caramels, or Maillards) andsoft nut paste fillings are good examplesof the type of centers that require shellmoulding for assembly. Centers likeganache or butter ganache are also suitedto this technique because they aredeposited at relatively cool temperature.

Layers of Flavors

Matching theproper assemblytechnique to the

centers is anotherkey to success.

Creating slabs ofthe layers, then

cooling, cutting andenrobing is the

most commonlyemployed method

of assembly.

94 April 2014 • The Manufacturing Confectioner

➤➤

Oil (low SFC) from the nuts moves into thechocolate. Cocoa butter from the chocolatemoves into the nut paste center.Result: softened chocolate and loss of texturalcontrast.

Figure 2

Fat Migration

Layers of Flavors

When layers thatare not heattolerant arecombined withcenters that aredeposited hot, theheat-sensitive layermust be depositedlast, regardless ofthe arrangement inthe finished piece.

The Manufacturing Confectioner • April 2014 95

➤

Processing Logistics

The order of layers within a piece greatlyinfluences the consumer’s eating experi-ence. Order affects how the consumerexperiences the flavors: which one comesfirst, which one lingers and how they meldtogether. Mouthfeel is even more greatlyaffected by the order of the layers within apiece. When there is a very firm or crisplayer, it generally makes sense to put it atthe bottom of the piece. In addition to fla-vor and texture, the order of layers alsoaffects the appearance of the cross sectionof the piece. All of these sensory consid-erations should go into planning how thefinished product will be composed.

The order of assembly is not necessarilyidentical to the finished arrangement, butis determined by the requirements of eachcenter. For instance, when layers that arenot heat tolerant are combined with cen-ters that are deposited hot, the heat-sensi-tive layer must be deposited last, regardlessof the arrangement in the finished piece.It is quite common practice to build lay-ered confections out of sequence or upsidedown in order to work with each of thecenters properly.

THE CENTERS AND THEIRCHARACTERISTICSXXXXXX

What follows is a brief summary of manyvarious confectionery centers and theircharacteristics with regards to making lay-ered confections.

Ganache is the quintessential artisan con-fectionery center. Its high Aw of about .80to .85 gives it a short shelf life, which, alongwith its cost, makes it generally unfeasiblefor large manufacturers to use. Consumerslove ganache, though, and it is a staple ofmany artisan confections. Ganache is sub-ject to moisture migration, and due to itshigh Aw will nearly always lose water tosurrounding centers or to inclusions.

Ganache cannot tolerate heat whendeposited, and so when used in conjunc-tion with centers that are deposited hot,the ganache must be the last layerdeposited regardless of its place within thefinished confection.

Butter ganache is a center that is seldomused in American confectionery, althoughit is well suited to artisan confections. Ithas a relatively high Aw of .70 to .75 and isprone to moisture migration. The high but-ter content also makes it prone to fatmigration, and like cream ganache, butterganache cannot tolerate heat whendepositing.

Noncrystalline sugar confections includecaramels, toffee, brittle and hard candy.These products all have low Aw and areall extremely hygroscopic. They will read-ily absorb moisture from other centers orfrom the atmosphere, resulting in crystal-lization and loss of quality. These centersmust be deposited while hot, and there-fore are deposited before layers that can-not tolerate heat.

Crystalline confections include fondant,fudge and crèmes. They are prone to mois-ture migration and have a relatively highAw in the range of .75 to .80. They there-fore have a tendency to lose moisture in alayered confection. Crystalline confectionsgenerally must be deposited while warm.

Marzipan has a relatively high Aw of .75 to.80, and so has a tendency to lose moisturein moisture migration. The oil from thenuts also causes fat migration, softeningthe firmer fats around the center such ascocoa butter.

Fat systems are mixtures of solids sur-rounded by fat, but containing no water.They include chocolate, gianduja (choco-late with nuts refined into it), nut pastessuch as peanut butter and praline paste,and meltaways, typically made with a lau-

ric fat to dramatically lower the meltingpoint. Fat systems are not subject to mois-ture migration, as they have no water togive up and do not absorb water in nor-mal shelf life. In fact, fat systems are alleffective barriers to moisture migrationbetween layers. Fat migration is a concernwith these centers, particularly with nutoils, which cause bloom and soften choco-late, and with meltaways made with lau-ric fat, which can soften chocolate, lowerthe melting point of cocoa butter and alsoresult in bloom.

Jellies make a great layer in confections.They are bright in color and vivid in flavor.They have a relatively low Aw of .60 to .75and are fairly hygroscopic, so moisturemigration must be considered when usingthem. Most jellies are deposited while hot, somust be deposited before layers that are notheat tolerant. As an aqueous system, jelliesare an effective barrier to fat migration.

Aerated confections, primarily nougat andmarshmallow, are widely used and appre-ciated centers in layered confections, bothartisan and in large production. Their Awvaries greatly depending on the total watercontent, whether the nougat is soft or firm,and whether it is a crystalline or noncrys-talline nougat, short textured or chewy.Like other sugar confections, the noncrys-talline nougats have a low Aw and arehygroscopic, while the Aw of the crystallinenougats is much higher. In either case, aer-ated confections are subject to moisturemigration and so may either tend to lose orgain moisture within a confection. Aeratedcenters must generally be either warm orhot when deposited.

THE INCLUSIONS AND THEIRCHARACTERISTICSXXXXXXXXX

Nuts and seeds are the most widely usedand appreciated inclusions in confectionsof every sort. They provide not only

crunchy textural contrast, but appealingflavors and healthful oils. Because nuts andseeds are resistant to moisture migrationand not adversely affected by the heat ofdeposited centers, they can be used freelyin a wide variety of centers, from ganacheto toffee and everything in between. The oilin nuts and seeds, however, does migrateinto more-solid fats. The more finely theinclusions are chopped or ground, and themore surface area is exposed, the moresevere the fat migration will be.

Dried fruit is a wonderful inclusion in con-fections. It has brilliant colors and won-derful flavors. Dried fruit is prone to mois-ture migration and will generally absorbwater due to its low water activity.

Cereals and farinaceous products Prod-ucts like cereals, pretzels and crackers canadd very interesting and unexpected tex-tures and flavors to layered confections.These inclusions have an extremely lowAw and will readily absorb moisture fromcenters if steps are not taken to mitigatemoisture migration, so they cannot be usedin centers containing water without firstcoating them with a barrier, such as fat, toprevent damage.

Rework Using rework as an inclusion inlayered confections is an opportunity tocreate unique textural and flavor effects.Many types of rework such as toffee, jellies,nougat and fudge can all be used in lay-ered confections. As an inclusion, reworkbehaves just as the center would withregard to migration of fat and water, sowhen using disparate rework and centers,steps must be taken to control and main-tain quality.

Figure 3 illustrates the practical appli-cations of various centers in confections asthey are likely to affect the artisan con-fectioner in the production and storageof composite candy bars. Susceptibility to

Layers of Flavors

Because nuts andseeds are resistant

to moisturemigration and notadversely affected

by the heat ofdeposited centers,they can be used

freely in a widevariety of centers.

96 April 2014 • The Manufacturing Confectioner

➤

Layers of Flavors

Susceptibility tomoisture migrationand fat migration,sensitivity to heat,the temperaturewhen depositingand whether thecenter cuts cleanly at roomtemperature are all importantconsiderations.

The Manufacturing Confectioner • April 2014 97

➤

moisture migration and fat migration, sen-sitivity to heat, the temperature whendepositing and whether the center cutscleanly at room temperature are allimportant considerations when composinglayered confections and planning assem-bly logistics.

The following are a few examples of lay-ered confections that I have created, andsome observations on why I think they aresuccessful.

The Salt & Pepper Bar (Figure 4) hasvery familiar flavors, but they are unusualwhen found within a confection. The barconsists of a layer of salted caramel and alayer of black pepper ganache. There istextural contrast between the chewycaramel and the creamy ganache. Applyinga fat barrier between the centers will mit-igate moisture migration and extend theshelf life. These bars are created in a slab,cooled, cut and enrobed. The caramel layeris deposited first when assembling becauseit must be deposited hot, and the ganachecannot tolerate heat.

Mint Madness (Figure 5) is made fromtwo different meltaways: chocolate mintand white chocolate. The creamy whitechocolate meltaway layer provides flavorand color contrast from the intense choco-late mint. Laminated peppermint hardcandy rework provides textural contrast.It would be very difficult to use the hardcandy rework in anything other than a fatsystem due to moisture migration and itshygroscopicity. Because it is so rich, thisbar is only about a half-inch high prior toenrobing. This bar was made in slab form,but meltaways can be deposited into shellmoulds as well.

The center of the Strawberry Temptress(Figure 6) has three distinct layers: a straw-berry pectin jelly, a tender, crystalline whitenougat and a thin, crisp layer of toastedalmonds embedded in dark chocolate. Inproduction, the nougat is deposited first,then the jelly, and, after cooling, it is flippedto add the chocolate almond layer. For cut-ting, enrobing and presentation, it is turnedback over so the strawberry jelly layer is on

Center Affected by Affected by Sensitive to Temperature Cuts cleanlymoisture migration1 fat migration high heat when deposited when cold

Chocolate N Y Y WarmGanache Y N Y Warm YButter Ganache S S Y Room temp YSoft Caramel Y N N Hot YToffee Y N N Hot NHard Candy Y N N Hot NFudge Y S N Warm YFondant Y N N Warm YMarzipan S S N Room temp YGianduja N Y Y Warm YMeltaway N Y Y Warm YJellies S N N Hot YNougat Y N N Warm to hot2 Y

InclusionsCereal/farinaceous Y N N Room temp YNuts N Y N Room temp YDried Fruit Y N N Room temp YConfectionery rework3

Y = Yes N = No S = Slightly1 Whether a center absorbs or exudes water depends on its Aw. 2 The temperature when depositing depends on the type of nougat. Hard nougats must be hotter when deposited.3 Confectionery rework as an inclusion has the same characteristics as when the products are used as centers.

Figure 3

Practical Applications of Centers and Inclusions in Confections

the top. This bar is also assembled in a slab,

cooled, cut and enrobed.

The Bimini Bar (Figure 7) is an example

of a shell-moulded layered confection fea-

turing the tropical flavors of coconut and

rum. The coconut layer is soft and doesn’t

have the standup that is required for slab-

bing, so shell moulding is the best option.

The rum ganache has a very similar Aw to

the coconut filling, so moisture migration

is not a problem. The textural contrast in

this bar is achieved not only from the two

different fillings but from the crisp choco-

late shell as well.

CONCLUSIONS

Layering multiple centers together in a sin-

gle confection creates some real opportu-

nities for artisans. By using existing for-mulas to greatly expand their product lineand combining more than one centerwithin a confection, artisans can creategreat flavor and textural combinations, andcompose unique signature items to differ-entiate their business and strengthen theirbrand. The major obstacles to success inlayered confections are moisture migra-tion, fat migration, applying the correctassembly technique to the centers and thelogistics of processing these complex con-fections. Understanding the obstacles, aswell as the properties of the centers andinclusions, will help to ensure success inmaking artisan layered confections. n

Figure 6

Strawberry Temptress Bar

Presented at the AACT National Technical Seminar

Figure 4

Salt & Pepper Bar

Figure 5

Mint Madness Bar

Figure 7

Bimini Bar

98 April 2014 • The Manufacturing Confectioner

By using existingformulas and

combining morethan one center

within a confection,artisans can create

great flavor and textural

combinations, and compose

unique signatureitems.

Layers of Flavors