Day 13 of #RCIAdvent is brought to you by Cocoa Day and another speak peak at this year’s issue of RCIScience Magazine!
From Bean to Bar to Belly:
The Science of Chocolate
by Kali Iyer
Modern chocolate did not really exist until the 1800s, when paste from the cacao plant was mixed with sugar to create what we now recognize as “chocolate”. Before this, the cacao plant was enjoyed by the Aztec and Inca peoples dating back to 600 CE. In this case, the cocoa beans would be roasted and ground using mill stones to produce a paste, which would then be added to water with spices and honey to produce a much-revered beverage.
When you ask someone what their favourite type of chocolate is, most people have a specific answer. There are strong proponents who push the extremes of pure chocolate, swearing 95% cacao is the only option, while others love the creamy sweetness of a white chocolate bar. Regardless of what camp you are in, the delights of chocolate are held near and dear to many people’s hearts - and bellies. But what really is chocolate and how is it produced? What do the many varieties of chocolate have in common? Food scientist Selvyn Simones shares his love of chocolate and the science behind it.
How is chocolate made?
Opening a cacao pod
Chocolate production starts with cocoa pods grown on the Theobroma cacao plant. Selvyn explains, “[these thrive] in the hot and humid climate of countries that fall along the Earth’s equator.” This includes major chocolate-exporting regions like Brazil, Indonesia, and West Africa. When the pods are harvested and cracked open, they reveal 30-50 seeds encased in a white substance called pulp, which has a pithy, lemon taste.
The pulp is then fermented by microbes for several days using the yeast and bacteria that naturally exist in the environment. That’s right, just like wine and bread, we have microbes to thank for chocolate. These microbes digest the pulp, producing many complex compounds that are critical to the chocolate flavour. These are absorbed by the seeds (now referred to as beans) over a period of days. The fermented beans are then laid out in the hot open air and dried out before roasting.
Roasting is a critical step involving a myriad of chemical reactions between the proteins and sugars within the beans. The shells are then removed, and the beans are broken into small pieces called cacao nibs. These are ground up further and sugar and spices are added. As the nibs are ground into miniscule particles, the fat, called cocoa butter, begins to separate out. First resembling wet sand, the mixture slowly evolves into a smooth, viscous, melted chocolate masterpiece. By this stage the true chocolate has taken form, and the chocolate particles, called cocoa solids, are so small that they have essentially dissolved into the cocoa butter, creating the smooth creamy sensation you experience when eating it. “One of the most remarkable things about chocolate is that it stays solid at room temperature, but becomes liquid at body temperature,” Selvyn pointed out. “[This creates] that luxurious melt-in-your-mouth quality.”
Types of Chocolate
What constitutes chocolate is a contentious subject. While many would agree that the three major types are white, milk, and dark chocolate, white chocolate doesn’t actually contain any cocoa solids, only cocoa butter and added milk fats, such as powdered or sweetened condensed milk. Cocoa solids and cocoa butter can be separated out during processing to create specific types of chocolate. As you increase the proportion of chocolate solids, you transition from milk to dark chocolate. The high percentage of milk fats in white chocolate lowers its melting temperature. This makes it melt faster in your mouth and gives it a creamy texture. The relative absence of these fats in dark chocolate results in a higher melting temperature and a waxier texture. In reality, every country has different regulations that determine what can legally be called chocolate, and how these three core types are distinguished. This is why chocolate bars in the United Kingdom or the USA taste different from those in Canada.
Tempering
“One of the most fascinating things about chocolate is that it can exist in six different solid states, called forms I to VI,” Selvyn explains. Each state is associated with a different organization of particles within the bar that presents different properties. Tempering chocolate is the process of adjusting the temperature to ensure that the chocolate hardens in form V, which produces shiny chocolate bars that snap when you break off a piece. If the temperature is just a little off the bar can solidify in form IV or lower, which takes on a crumbly texture, or form VI, where the chocolate has a white coating on the surface called a chocolate bloom. Most of us will have seen the chalky chocolate bloom on old, forgotten Halloween candy, or if you leave chocolate in your hot car. Despite all the time and money invested in understanding chocolate, we still don’t know exactly how chocolate adopts its form VI state.
The production of chocolate spans numerous disciplines, encompassing the intricacies of its scientific manufacturing, the nuances of its legal definitions, and the economic and environmental implications of its popularity. For a substance that has been around for centuries, the world of chocolate is still shockingly dynamic. In 2017, after more than a decade of development, the Belgian-Swiss company Barry Callebout unveiled a brand new class of chocolate to the world called Ruby chocolate. Derived from a different variety of cacao pod which undergo a slightly altered fermentation process, this chocolate has a sour, fruity flavour, and most strikingly, a naturally brilliant pink colour. Its development only highlights how much more there is to explore and understand about this much revered substance, by both professionals and chocolate enthusiasts alike.
Learn more in The Science of Chocolate, over on YouTube now!