Chocolate persists in its appeal
Aug. 1, 2015
by Ryan Atkinson
Although no one is necessarily making a claim in opposition, the point is worth making: Chocolate isn’t going anywhere. Cocoa sits behind only vanilla as the most popular food flavor in the Western hemisphere, according to the fourth edition of Baking Science & Technology.
Consumers can find many things to love about the products and creations that derive from cocoa beans, nibs and chocolate liquor. Among its numerous forms, it can be sweet, bitter, smooth, dark and white. And as recent findings suggest, indulging in chocolate and other cocoa ingredients may not be as unhealthy as once believed.
All that said, while chocolate carries a high appeal to consumers, it also brings along temperamental in-plant handling qualities. With the rumors of chocolate’s potential shortage having been exaggerated and the simple ingredients trend favoring the use of real chocolate over coatings, now is as good a time as any to take a closer look at how to maintain chocolate’s quality during storage and use.
Back to the basics
When having any discussion about cocoa, it’s never a bad idea for a quick refresher on the processes that result in the ingredients used for chocolate products.
It all starts with the Theoberoma cacao tree and the beans it produces. The beans — cocoa beans — from two species of T. cacao trees account for nearly all of the commercial harvest. Forastero provides the bulk or “base” beans and Criollo gives us the “flavor” beans. The beans are roasted to develop the typical flavors and dark colors we associate with chocolate. The nibs then go through a grinding process that releases the bean’s fat, or cocoa butter, and leads to chocolate liquor. Chocolate liquor is the basic starting material for all chocolate products. It undergoes conching if destined for chocolate production. It can be moulded into bars, chips, nuggets, chunks and many other small shapes and sold as baking chocolate, either as milk or dark. Chocolate powder is used in dry mixes and drinks.
The big bloom
Bloom, whether sugar bloom or fat bloom, is one of the biggest issues facing bakers who use chocolate. Both result in an unsightly and undesirable white residue on the chocolate.
“You can identify the difference between both types of bloom by rubbing your finger on the surface of the chocolate,” said Mark Adriaenssens, vice-president, R&D, Barry Callebaut, Chicago. “While rubbing it, the fat bloom will disappear while sugar bloom will not. The sugar bloom will also result in more of a rough surface.”
Fat bloom has everything to do with temperature. It can form as a result of inadequate tempering or temperature abuse of well-tempered chocolate.
“It is generally the outcome of excessive heat attacking the cocoa butter crystals,” said Julie Eno, associate marketing manager, Cargill Cocoa & Chocolate, Lititz, PA. “Fat bloom produces a visible film on the surface, ranging from a dull white to a severe white discoloration, and soft or crumbling interior textures.”
Stacey Kidd, marketing communications manager, Blommer Chocolate, Chicago, pointed out that fat bloom occurs when the chocolate isn’t in the proper crystal structure, which can come from a number of causes. If the chocolate isn’t properly tempered in the first place, it will most likely bloom. It is also likely to happen without proper cooling — generally a gradual cooling with the coldest part of the cooling tunnel being in the center — which is necessary for chocolate to set in the correct structure. Fat bloom can also occur if the product has been exposed to temperatures high enough to melt some of the crystals after use. For enrobed items, this can happen if the center of the product is too warm in addition to improper outside conditions.
“It can be from other fats and oils migrating through a chocolate,” Ms. Kidd said. “Nuts are of particular concern here.”
High storage temperatures or a storage area with changing temperatures can cause the fat (cocoa butter) to melt and move to the surface, where it recrystallizes in a different shape, resulting in the white dusting. Good tempering and cooling at the moment of moulding the chocolate can keep it at the correct and stable temperature.
“Also, some ingredients can naturally help reduce blooming,” Mr. Adriaenssens said. “An example is that some milkfat in a dark chocolate will reduce the risk of fat blooming.”
Despite its negative looks, the product remains perfectly safe to eat and can be re-tempered to reach the desired appearance.
Sugar bloom, on the other hand, is all about humidity. It occurs when moisture forms on the surface of the product, subsequently dissolving the sugars. Once the surface dries out, the sugars recrystallize.
“Sugar bloom is usually caused by the humidity in the room being too high during packaging, or products giving off moisture after packaging,” Ms. Kidd said. “Controlling the environmental humidity and the water activity of your products are the best ways to control sugar bloom.”
Unlike the dull film of fat bloom, sugar bloom leads to coarse sugar crystals on the surface of the chocolate; picture a hard, white surface film. Another difference is the product’s usability after substantial bloom.
“If sugar bloom is slight, the product may be salvageable once all bloom is removed,” Ms. Eno said. “But if sugar bloom is moderate to severe, the product should most likely be discarded.”
Handle with care
As the fat and sugar bloom dilemmas highlight, proper storage is vital to keeping chocolate and cocoa in as good a condition as possible.
While exact numbers and ranges may vary depending on location, “cool and dry” is the way to go for storing both raw materials and finished goods. Mr. Adriaenssens set the ideal conditions at somewhere between 45 and 68°F and a relative humidity of less than 70%.
Ms. Eno’s definition of cool and dry runs from 55 to 65°F with a relative humidity of less than 50%. She also pointed out that, as a raw material, cocoa should be in an area free of any foreign odors and that chocolate should be kept off the floor. Ms. Kidd, meanwhile, set the temperature range between 60 and 70°F (110 to 120°F for liquid form) with a maximum humidity of 60%.
“This can be challenging in a bakery, but it should be kept in mind when thinking about the logistics of the product,” Ms. Kidd said. “Product should not be refrigerated or placed in the freezer because this will cause condensation to form.”
In addition to the temperature of storage, the shelf life of a confectionery or chocolate product depends on its ingredients and its packaging. The sugar content of chocolates and its typical storage in solid form at room temperature can lead to a rather long shelf life. Cocoa powders, cocoa butter and chocolate liquor can last longer than two years, according to
“Deodorized cocoa butter may have some of its naturally occurring antioxidants removed, causing shelf life to be reduced,” she said. “Dark chocolates age quite nicely and actually will get better with age. Milk chocolates also have a great shelf life, but not as good as dark chocolates due to the milk ingredients present. White chocolate will have slightly less shelf life than milk chocolate because of its high milk content, the lack of cocoa solids and loss of natural antioxidants protecting the product.”
Vegetable fat-based products — a.k.a. compound or confectionery coatings — should be evaluated at one year. Sensory testing is recommended at shelf life limits to determine the quality of the stored ingredients.
Tame your temper
Just as important as storage is monitoring chocolate during production, especially when using tempered chocolate.
The white paper “Chocolate Temper Measurement” from Tricor Systems, Inc., Elgin, IL, defined a good chocolate temper as the physical state having the largest number of the smallest crystals of the right crystalline form. The large number of crystals is desirable because the amount of cocoa butter set as chocolate is a function of the seed crystals. The small size of the crystals will not affect chocolate’s flow properties, among other things. Over-tempered chocolate can thicken and become difficult to transport and deposit. Well-tempered chocolate, on the other hand, remains at a relatively constant viscosity.
“When enrobing or moulding chocolate, a good temper of the chocolate is indeed crucial, and conducting consistent checks of the temper is recommended,” Mr. Adriaenssens said. “A good temper will give you the shiny looking product with a good snap that is desired with chocolate. Also, a good temper and proper cooling will avoid or delay fat bloom.”
Ms. Eno suggested checking the temper a few times per shift, or once every hour or two, and noted that there are multiple ways to do so. One method involves dipping a metal spatula or knife blade into the chocolate so that it leaves a thin film on the blade.
“If the chocolate is firm and not tacky in five minutes at normal room temperature, it is in good temper,” Ms. Eno said. “If it is still tacky, place chocolate chunks back into a bowl and cool about 2 F° and then repeat the test until tempered.”
A metal spatula can also be placed in a cool spot — a refrigerator is fine — and then examined. The chocolate should be solidified and glossy, not tacky, to the touch. Bakers can also perform sensory evaluations of the product. Is it shiny? Does it snap audibly when broken? Are there any cloudy parts on the surface?
Once bakers have determined the best temper for a process, temper meters are an option to keep chocolate at optimum conditions. According to the paper from Tricor, temper meters do not measure the quality of temper; instead, they quantify the crystal growth process for an identical product formulation at the same location on a product line. It repeatedly measures the heat of crystallization.
“It is ideal to have a chocolate temper meter on hand to test real time data throughout your process,” Ms. Kidd said. “If working with tempered liquid chocolate, it is ideal to test the temper of the enrobing chocolate every hour. This will ensure there is minimal drift of temper during the chocolate application and will minimize the risk of bloom. The meter test takes only five minutes and produces excellent readouts that are easy to interpret.”
Baked items that use chocolate as an inclusion are not impacted as greatly by temper. Essentially, the temper of the chocolate chip, chunk or drop is lost during baking.
“Because of this, a baker can, in some cases, get away with using bloomed chips in a baked application,” Ms. Eno said. “That is why proper cooling is so critical to prevent bloom after baking.”
Regardless of preparation and monitoring, problems are inevitable. A good plan for troubleshooting can help pinpoint the cause and develop a solution.
“There are ways to resolve issues when problems occur with chocolate, but it really depends on what the problem is and determining the appropriate solution to be implemented,” Ms. Eno said. “Once the true issue is assessed, corrective and revised handling protocols can be changed.”
One example could be chocolate chip bloom within a cookie, which is generally caused by improper cooling of the cookies after baking. Adapting the cooling process could solve the issue.
Ms. Kidd recommended a solid understanding of the processing line as the foundation for troubleshooting. After ensuring that the product is in good temper, a baker can begin investigating line conditions that impact the product after the application of chocolate.
“Data loggers are great,” Ms. Kidd said. “We recommend one that measures humidity as well as temperature. You can run them through your cooling tunnel to check the cooling profile or even package them up with the product to get a perspective on storage and distribution conditions. And always remember to check your airflow and blowers in the cooling tunnel to ensure cool, tempered air is pumping through.”
It all adds up to better, more efficient ways to store and use chocolate, and with cocoa supply questions flying around, it’s never a bad time for bakers to be on top of their game.