Chocolate-WCC STEM Scholars Newsletter July 2023

By Martin Gargaro In 1964, the renowned British author Roald Dahl published one of his, if not overall, most famous children's novels of all time: Charlie and the Chocolate Factory. It tells the story of Charlie Bucket, a poor boy who gets a golden ticket to visit a whimsical factory run by the mysterious and slightly nutty Willy Wonka. He is accompanied by four other kids with bratty behavioral traits. Throughout the tour, both the characters and the reader experience a variety of incredible sights, such as a candy forest with peppermint ferns, jawbreaker rocks, lollipop trees, and even a chocolate river with a candy boat, a candy laboratory that can make all sorts of bizarre and unimaginable sweets, a workshop where squirrels are trained to break open and separate nuts to be used in the toffee and chocolates, and a teleportation room for Wonka's chocolate bars. During the tour, the four bratty kids are expelled after falling victim to their own selfish desires. This results in Charlie becoming the next heir of the factory as a reward for his good character. The story has been adapted several times, including two movies (the first from 1971 starring Gene Wilder as Willy Wonka and Peter Ostrum as Charlie Bucket, the second from 2005 starring Johnny Depp as Willy Wonka and Freddie Highmore as Charlie Bucket), as well as theater productions and even a former attraction at Alton Towers theme park. Although such an experience can only be found as a result of Roald Dahl's imagination, the process of how real chocolate factories produce the delicious confection is nonetheless fascinating.

Considering how many people enjoy eating chocolate-covered fruits like cherries, bananas, or strawberries, it may be surprising to know that chocolate itself comes from a fruit. This fruit, called the “cacao pod” (Spanish for cocoa), grows from a tropical evergreen tree of the same name (Theobroma cacao). Although cacao trees are native to Central and South America, there are farms in Africa and Southeast Asia as well. In fact, it is these farms where most chocolate comes from. The best quality chocolate happens when the trees are planted underneath the canopy of the rainforest, so they have the proper balance of light and shade. Inside the pods are the cocoa beans, which are used to make chocolate. The timing for harvesting the pods has to be just right. If they are harvested too soon before they are ripe enough, the distinct flavor that the beans give chocolate will be bland. If they are harvested too late after they ripen, the beans may start sprouting on their own and will be useless for chocolate-making. Harvesting itself is also a painstaking process as well; the farmers have to be cautious about not damaging the rest of the tree when cutting the pods down. Many nations harvest the pods between May and December. After harvesting, the pods are then split open to get to the beans inside. Each pod can contain as many as forty beans encased in a white or light-brown pulp which are then scooped out and fermented for roughly a week. In the traditional process, the beans are wrapped up in banana leaves and set out in the sun. The heat causes the organic compounds inside the pulp to be broken down and turned into alcohols by its natural yeasts and microorganisms. The beans then absorb the alcohols, giving them the distinct smell and flavor of chocolate. Although many modern-day productions don’t wrap the beans in banana leaves, the fermentation process is still nonetheless the same. The beans are then dried out for about two weeks. There are two major reasons as why this is a vital process. For starters, less moisture means there’s less likelihood for mold or bacteria to grow. Furthermore, the drying process creates further chemical changes responsible for the flavor of the beans. There are commercial drying plants to speed up the process, but drying out the beans in the sun provides the highest quality cacao. After the beans are dried, they are loaded into sacks and shipped off to the warehouses of manufacturers. This is where we finally get to go to the chocolate factory.

Much like a walnut, the edible part of the cocoa bean (known as the “nib”) is protected by an outer shell. In order to remove that shell, the beans need to be roasted in large, rotating cylinders at a temperature between 240-300 degrees Fahrenheit. This is arguably the most critical step in producing high-quality chocolate. Not only does it make the shells brittle enough to remove, but it also causes Maillard reactions. Maillard, or browning, reactions occur when sugar and protein are brought together and react under high heat, resulting in the compounds that produce a distinct color, flavor, and even aroma, thus making roasting the final step in bringing out the finished qualities of chocolate. Maillard reactions are also responsible for bringing out such qualities in coffee, baked goods, toasted marshmallows, caramels, and even cooked meat, albeit they have differences as a result of the different types of sugars and proteins present. Depending on how long the beans are roasted and/or the level of heat, it can result in a variety of different colors and flavors, so roasting itself can more or less be considered an art form. It is, however, a delicate process between making sure that the beans are roasted enough for the shells to come off, but not to the point of burning the nibs. After roasting, the beans are processed through a winnowing machine to remove the shells. The shells are cracked open by rollers and then blown off the nibs by powerful fans. While the nibs are taken to be processed, the shells are sometimes used to make an organic mulch, which is rich in nitrogen, phosphate, and potash. When watered, the cocoa bean mulch releases a nice chocolate aroma.

Every chocolate company, from Hershey’s to Lindt & Sprüngli to Nestlé to Mars, Incorporated, has their own unique recipe for their chocolates, which are made by combining different cocoa nibs from different sources, different types and different amounts. After being blended together, the cocoa nibs are sent to mills where they are ground into a paste called chocolate liquor. The more the nibs are ground, the smoother the liquor. The term chocolate liquor is a bit of a misnomer, as it contains no alcohol; it actually is attributed to its liquid qualities. This is why it is sometimes referred to as cocoa mass. There are two paths that can be taken with chocolate liquor. The first path is that some of the liquor is solidified and crushed in hydraulic presses to squeeze out and separate the "cocoa butter", the fat found in cocoa beans. The remaining residue, known as "cocoa solids", is then ground further to produce cocoa powder. Cocoa powder is used to make hot chocolate mix and as flavoring by dairy companies and bakeries. Cocoa butter is the only vegetable fat solid at room temperature, but it melts at body temperature. These qualities are why cocoa butter is widely used in cosmetic products and other toiletries. This is also why it is a vital ingredient in the final product of chocolate as it provides that smooth, melt-in-your-mouth texture that chocolate is known for. This brings us to the second path that chocolate liquor can take, and that is the chocolate we like to eat.

When making the final product, the chocolate liquor is combined with even more cocoa butter (though not necessarily the same butter removed earlier in the process), along with sugar and other ingredients and flavorings, depending on the type of chocolate being made. These ingredients are blended together in a process called "conching", designed to break up crumbs and make the flavor and texture mellow throughout. Depending on the chocolate company and its recipes, conching can take anywhere from a few hours to a few days. Finally, the chocolate is poured into a kettle in which it is heated and cooled repeatedly in a process called "tempering". Since cocoa butter contains different fats that cool and harden at different temperatures, stirring while tempering ensures these fats are spread around and cooled more evenly. The most important part about tempering is that it helps chocolate crystals form in an orderly way so the finished chocolate is glossy and smooth in appearance and has a nice, clean break. Most chocolate products, such as bars or seasonal candies (Christmas, Easter, etc.), are made by pouring the liquid into specially shaped molds. When filled, the molds take a slightly bumpy ride to remove any air bubbles and allow the chocolate to settle evenly. Finally, they make their way through a cooling tunnel where the liquid chocolate is slowly chilled into a solid candy. Chocolate chips, on the other hand, are made a little differently. Special machines drop a small, precise amount of chocolate onto a conveyor belt and then quickly cool it to form a distinct chip shape.

Although chocolate can come in a variety of forms (such as dips, powders, syrups, chips, and bars) and have a vast assortment of different ingredients, including mint, nuts and crispy pieces, chocolatiers recognize the confection into four main categories: dark chocolate, milk chocolate, white chocolate, and ruby chocolate. The first category, dark chocolate, is often regarded as the purest form of chocolate. Since it is essentially just the chocolate liquor with some extra cocoa butter and sugar added, dark chocolate is the closest thing we have to the taste of pure cocoa. This leads us to the second category: milk chocolate. As the title applies, milk chocolate is made the same way as dark chocolate, except powdered or condensed milk (usually sweetened) is added to the mix, along with vanilla. The presence of dairy solids, along with the added flavorings, offsets that of the cocoa solids, resulting in milk chocolate having a sweeter taste and creamier texture as opposed to the more bitter taste and crisper, chalkier texture of dark chocolate. The third category, and probably the more controversial, is white chocolate. White chocolate is made very similarly to milk chocolate, except it does not contain chocolate liquor or cocoa solids, and is instead made just with cocoa butter. Because of this, it is debated among chocolatiers as to whether white chocolate should truly be classified as chocolate. The fourth and final category, and also the most recent one is ruby chocolate. First introduced back in 2017, ruby chocolate is created with the beans of a cacao tree subspecies known as the ruby cacao, found in Ecuador, Brazil and the Ivory Coast. It is well- known for its distinctive reddish-pink coloration as well as a somewhat tangy taste, similar to berries. This is due to the presence of citric acid in the chocolate. Although it does contain cocoa solids, unlike white chocolate, there is still some controversy as to whether ruby chocolate is truly chocolate or if its just a gimmicky confection.

Once the chocolate products have cooled and passed inspection, they are packaged, sealed for freshness, stamped with the company’s branding and shipped off to be sold. When shipping, chocolate products must be kept dry and at a consistent temperature, otherwise a whitish film of cocoa butter, called a “bloom”, could develop on the surface. Although it has no effect on the flavor or performance of the chocolate, it certainly impacts the quality of both appearance and texture. Chocolate is a big business, bringing in almost $150 billion a year worldwide, $30 billion in the United States alone, and the reason why is more than understandable. It is one of the most popular confections ever, enjoyed by millions of people ever since the days of early Mesoamerican civilizations, and served as the basis for one of Roald Dahl’s most beloved stories. So, the next time you buy a chocolate bar for yourself or give a box of chocolates to your date, remember all the hard work that went into making it, and not just the workers and chocolatiers at the factory, but also the natural workers. The sun and rain that grew the cacao tree, the insects that pollinated the tree to grow the pods, the local villagers that harvested the pods to get the beans, and the yeasts and microorganisms that fermented the beans to give it the flavor we love.

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