The Chocolate – The most deliciously engineered material on Earth_Part 2_ Where does the Chocolate comes from?

Chocolate is a key ingredient in many foods such as milk shakes, candy bars, cookies and cereals. It is ranked as one of the most favourite flavours in North America and Europe. Despite its popularity, most people do not know the unique origins of this popular treat. Chocolate is a product that requires complex procedures to produce. The process involves harvesting cocoa, refining cocoa to cocoa beans, and shipping the cocoa beans to the manufacturing factory for cleaning, roasting and grinding. These cocoa beans will then be imported or exported to other countries and be transformed into different type of chocolate products.

Chocolate production starts with harvesting cocoa in a forest. Cocoa trees, such as Theobroma Cocoa, grow in tropical climates, in wet lowland of Central and South America, West Africa and Southeast Asia and produce fruit in the form of large fleshy cocoa pods. These look like some form of wild and leathery orange or purple melon. The pods grow directly out of the trunk of the tree, not from a branch – they are about the size of a football – making them seem suspiciously unevolved and prehistoric. You can imagine dinosaurs trying to eat them (and spitting them out). Inside each pod there are 30 to 50 soft, white, fat almond-shaped seeds the size of small plums. Fresh cocoa beans are not brown at all, they do not taste at all like the sweet chocolate they will eventually produce.


Hence no discussion of good chocolate can be complete without delving into the origin of the fruit, and its varieties. Scientists at the International Center for Agricultural Research and Development (CIRAD) believe that the world’s original Theobroma could be millions of years old, and the particular species we now regard as the cocoa tree could be about 10 to 15 thousand years old. The cocoa plant first appeared in the Amazon basin, and was likely domesticated by the Olmecs civilization, predating the Mayans. For the next 3 to 5,000 years, the Mesoamerican civilizations including the Olmecs, Mayans and Aztecs cultivated and domesticated the T. Cacao plant extensively. The fermented and dried cacao beans were regarded as “food of the gods,” and also used as a form of currency.

There are 4 main varieties of the cacao plant, these are: 

  1. forastero,
  2. criollo,
  3. trinitario,
  4. nacional.

Both the criollo and forastero variety originated in the Amazon basin. And while the criollo is delicate and difficult to cultivate, the forastero variety being easier and hardier made its way to Spanish, Dutch, and Portuguese colonies in west Africa, south Africa, and southeast Asia. The 1700’s brought upon a new variety of cacao beans in the Caribbean islands. Disease and disaster eradicated almost all the criollo cocoa plants, until farmers on the islands planted forastero to strengthen what remained. This hybrid strain is now known as trinitario.

FORASTERO COCOA = Forastero  variety still dominates in world chocolate production. The high yielding plants of forastero made it an easy choice for growers, and even up until the mid 20th century, growers replaced the criollo  crop with the low quality forastero for this reason. (Think of forastero  as your regular grocery store tomato, and the criollo as that heirloom tomato that creates tastes explosions in your mouth.) Forastero is primarily cultivated in West Africa and is known as bulk cocoa. This cocoa is generally earthy and simple. This pod is usually short and yellow.

CRIOLLO COCOA = Due to its fragile state, susceptibility to disease, and low production, criollo  plants now make up less than 1 to 5% (the experts vary on that number) of the total crop production in the world. Partly due to the rarity, and definitely due to its unique, complex flavor, criollo  beans are regarded as super fine cocoa and many heirloom varieties are sought after by craft chocolate makers. Within the criollo variety, there are porcelana, chuao, ocumare beans, referencing a particular terroir of the criollo bean. Criollo cocoa is often fruit forward, very aromatic, and has very little bitterness. When this pods are ripe they are usually long, red or yellow.

TRINITARIO COCOA = Trinitario  beans while not as rare as criollo still only make up less than 10% of the total cocoa production. This hybrid strain spread from the Caribbean islands to South America in the 19th and 20th centuries. The Trinitario being the least pure has the a wide range of tastes and profiles of any other variety. The ratios of criollo to forastero, and terroir greatly influence the complex flavors found in this bean. This particular one is a cross between corillo and forastero,the pods are either lonh or short,yellow or red.

NACIONAL COCOA = The least known cocoa, and fourth variety is nacional. This bean variety was only recentrly redicrovered in Peru in 2011. In its purest form, it is regarded as the world’s rarest cacao. Chocolates made with nacional  beans are rich, creamy, and with little bitterness.

This is how all chocolate is made:

Cocoa needs to be harvested manually in the forest. Machines could damage the tree or the clusters of flowers and pods that grow from the trunk, so workers must harvest the pods by hand. The pods start out green and turn orange when they’re ripe. When the pods are ripe, harvesters travel through the cocoa orchards with machetes and hack the pods gently off of the trees. The farmers cut the outer peel of the cocoa pods open with long knives to collect the fruit pulp inside and then deposited them in a heap on the ground. This natural process removes any of the remaining fruit pulp around the beans.

Over 2 weeks the heaps of beans start to decompose and ferment, and in the process they heat up. During fermentation, the beans change from gray to brown to purple and develop their aroma. After fermenting, the cocoa beans are spread out and left to dry in the sun for about 6 days. This serves the purpose of “killing” the cocoa seeds, in as much as it stops them from germinating into cocoa plants. But more importantly it chemically transforms the raw ingredients of the cocoa bean into the precursors of the chocolate flavours. If this step doesn’t take place, whatever else you do, you won’t get anything remotely like chocolate.

It is during this fermentation that the fruity ester molecules are created, the result of a reaction between the alcohols and the acids that are created by enzymes acting within the cocoa beans. As with all chemical reactions there are a vast number of different variables that affect this outcome, such as:

  • the ratio of the ingredients,
  • the surrounding temperature,
  • the availability of oxygen …and many others.

This means that the taste of chocolate is highly dependent not just on the ripeness and species of the cocoa bean, but also on how high the rotting piles of beans are stacked, how long they are left to rot and generally what the weather is like. After the cocoa pods are dry enough, they are collected into baskets, thousands of sacks of cocoa are taken from the collection centers to huge warehouses. The beans, packed in sacks or containers, are then shipped to the cocoa processing houses. Here they are split open and the cocoa beans are removed, then they are send to chocolate producing sites in Europe, America and Asia.

If all this makes you wonder why chocolate makers rarely talk about these subtleties, it is because they are a secret. On the face of it cocoa seems to be like other commodities: a basic ingredient, like sugar, that is bought and sold on world makers, fuelling a billion-dollar industry in edible products. But what is much less talked about is that, just like coffee and tea, different varieties of bean and different techniques of preparation create vastly different tastes. A detailed understanding of both is required to buy the right beans and when it comes to creating the finest chocolates this knowledge is closely guarded.

Controling quality, meanwhile, also means taking into account the variability of tropical weather and the sporadic influx of disease. All in all, producing quality chocolate requires a huge amount of care and attention, which is why good dark chocolate is expensive. What you get for money, though, is not just the delicate fruity flavours from the fermented esters, but a set of earthy, nutty, almost meaty flavours. These are produced in the process that comes after fermentation, when the beans are dried and roasted. As with coffe making, roasting turns each bean into a mini chemical factory, in which a new set of reactions takes place. First, the carbohydrates within the bean, which are mostly sugar and starch molecules, start to fall apart because of the heat. This is essentially the same thing that happens if you heat up sugar and starch molecules, start to fall apart because of the heat. This is essentially the same thing that happens if you heat up sugar in a pan: it caramelizes. Only in this case the caramelizing reaction takes place inside the cocoa bean, turning it from white to brown and creating a wonderful range of nutty caramel flavour molecules.

The reason why any sugar molecule – whether is a cocoa bean or a pan or anywhere else – turns brown when heated is to do with the presence of carbon. Sugars are carbohydrates, which is to say that they are made of carbon (“carbo-“), hydrogen (‘hydr-‘) and oxygen (‘-ate’) atoms. When heated, these long molecules disintegrate into smaller units, some of which are so small that they evaporate (which accounts for the lovely smell). On the whole, it is the carbon-rich molecules that are larger, so these get left behind and within these there is a structure called a ‘carbon-carbon double bond’.

This chemical structure absorbs light. In small amounts it gives the caramelizing sugar a yellow-brown color. Further roasting will turn some of the sugar into pure carbon (double bonds all round), which creates a burnt flavour and a dark-brown color. Complete roasting results in charcoal: all of the sugar has become carbon, which is black.

Another type of reaction, which occur at a higher temperature, also contributes to the colour and flavour of the cocoa: the Maillard reaction. This is when a sugar reacts with a protein. If carbohydrates are the fuel of the celular world, proteins are the workhorses: the structural molecules that build cells and all their internal workings. Seeds (in the form of nuts or beans) must contain all of the protein needed to get the cellular machinery of a plant up and running, so there is plenty of protein in the cocoa beans. When subjected to temperatures of 160°C and above, these proteins and carbohydrates start to undergo Maillard reaction, reacting with the acids and esters (produced by the earlier fermentation process) and resulting in a huge range of smaller flavour molecules. It is no exaggeration to say that without the Maillard reaction the world would be a much less delicious place: it is the Maillard reaction that is responsible for the flavour of bread crust, roasted vegetables, and many other roasted, savoury flavours. In this case, the Maillard reaction is responsible for the nutty, meaty flavours of chocolate, while also reducing some of the astringency and bitterness.

Grind up the fermented and roasted cocoa nuts and add them to hot water and you have the original hot “chocolate” made by Mesoamericans. The Olmecs and then the Mayans, who 1st cultivated chocolate, drank in this way, and it was revered as a ceremonial drink and an aphrodisiac for hundreds of years. The cocoa nuts were even used as currency. When European explorers got hold of the drink in the 17th century, they exported it to coffee houses, where it competed with tea and coffee to be the beverage of choice of Europeans – and lost. What no one had really mentioned was that “chocolate” means “bitter water”, and even though it was sweetened with the new cheap sugar flooding in from the slave-run plantation of Africa and South America, it was also a gritty, oily and heavy drink, because 50% of the cocoa bean is cocoa fat. This is how it remained for another 200 years: an exotic drink, notable but not terribly popular.

With the intervention of a few industrial processes, though, chocolate’s fortunes suddenly changed. The 1st was the screw press, invented by a Dutch chololate company called Van Houten in 1828. Crushing the fermented roasted beans with this press forced the cocoa butter to flow out and allowed Van Houten to separate it from the remaining cocoa solids. Now free of much of its fat, the cocoa could be ground down into a much finer powder and so lost its grittiness, becoming smooth, sleek and velvety. It was in this form that cocoa now became popular – and survives to this day – as drinking chocolate. Then came a moment of counter-intuitive genius: having removed and purified the cocoa fat, and having pulverized the cocoa powder separatelly, why not mix them back together again, adding in some sugar, to create an ideal cocoa bean – the kind of bean you would want to pick from a tree, the kind of bean with exactly the right combination of sugar, chocolate flavour and fat that would exist in a Willy Wonka world?

There were many chocolatiers in Belgium, Holland and Switzerland who experimented with this appoach, but it was an English firm called Fry and Sons who became famous for producing such nodules of “eating chocolate” and in doing so created the 1st chocolate bars. As the purified cocoa butter melted in the mouth, it released the cocoa powder, producing instant hot chocolate in the mouth – a sensaton that was completelly unique. Because the cocoa fat content could be controlled separately from the cocoa powder and the sugar, it was now possible to design different types of sensation in the mouth to suit different tastes. And in a time before refrigerators, the cocoa butter’s antioxidant properties meant that chocolate made in this way had a long enough shelf live to become a commercial product. The chocolate industry was born.

For some, even with the addition of 30% sugar, this form of chocolate was still too bitter, and so another ingredient was added, one that profoundly affected its taste: milk. This reduces the chocolate’s astrinngecy quite considerably, givin the cocoa an altogether milder – and the resulting chocolate an altogether sweeter – flavour. The Swiss were the 1st to do this in the 19th century, adding the plentiful milk powder produced by the fledging Nestlé company, which itself was transforming milk from a local fresh product with a short life into a transportable commodity with a long one. The merging of the 2 commercial products, both with a long shelf life, was an enormous hit. These days the type of milk added to chocolate varies widely throughout the world, and this is the main reason that milk chocolate tastes different from country to country. In the U.S.A. the milk used has had some of its fat removed by enzymes, giving the chocolate a cheesy, almost rancid flavour. In the U.K. sugar is added to liquid milk and it is this solution, reduced into a concentrate that is added to the chocolate, creating a milder caramel flavour. In Europe powdered milk is still used, givin the chocolate a fresh dairy flavour with a powdery texture. These different tastes do not travel well. Despite globalization, the preferred taste of milk chocolate, once acquired, remains surprisingly regional.

One thing that all milk chocolate has in common, though, is that almost all of the milk’s water content has been removed before it is added. This is because chocolate powder is hydrophilic (water loving): given a chance it will absorb water, but in doing so it will eject its fat coating (water and fat will not disolve in one another), in the process decomposing into a lumpy liquid, much like the Mayan chocolate. Anyone who has ever tried to add water to melted chocolate to create a sauce will have experienced this problem.

There are plenty of people, including myself, who are addicted to eating chocolate, and the reason may not just be its taste. it also contains psychoactive ingredients. The most familiar one is caffeine, which is present in small proportions in the cocoa bean, and so ends up in the chocolate via the cocoa powder. The other psychoactive ingredient is theobromine, which is a stimulant and antioxidant, like caffeine, but is also highly toxic to dogs: many dogs die every year from eating chocolate, maily around Easter and Christmas. Theobromine’s effect on humans appears to be much milder, and the stimulant levels in chocolate are small when compared to coffee and tea, so even if you eat a dozen chocolate bars every day, it is only equivalent to drinking one or two cups of strong coffee. Chocolate also contains cannabinoids, which are the chemicals responsible for the high experienced from smoking dope. But again the percentage are tiny, and when blind taste studies were carried out to analyse chocolate cravings, researches found little evidence that any of these chemicals were linked to feelings of craving.

This leaves another possibility to explain chocolate addiction that rather than its being a chemical effect, it may be that the sensory experience of eating chocolate is itself addictive. Chocolate is like no other food. When chocolate melts in the mouth it suddenly releases a wild and complex, sweet and bitter cocktail of flavours within a warm rich liquid. It is not just a flavour but an entire oral experience. It is soothing and comforting, but it’s also exciting and – not to put too fine a point on it – seems to satisfy more than a physical hunger. Some say that eating chocolate is better than kissing, and scientits have dutifully tested this hypothesis by carrying out a set of experiments. In 2007, a team led by Dr. David Lewis recruited pairs of passionate lovers, whose brain activity and heart rate were monitored first while they kissed each other and then while they ate chocolate (separatelly). The researchers found that although kissing set the heart pounding, the effect did not last as long as when the participants ate chocolate. The study also showed that when the chocolate started melting, all regions of the brain received a boost far more intense and longer lasting than the brain activity measured while kissing. Although this is just a single study, it does give credibility to the hypothesis that for many the sensory experience of eating chocolate is better than kissing. This association of chocolate with extreme sensory pleasure has been energetically promoted by chocolate manufacturere, most notably, perhaps, in the long-running television advers for Cadbury’s Flake.

These adverts, which began in the late 1950s but continue to this day, always feature a woman relaxing on her own while indulging in the secret pleasure of eating a Flake. The shape and size of this rod-like chocolate, and the suggestive manner in which the women indulged in it, were enough to send waves of outrage and alarm through the viewing public, despite the fact that the adverts never showed any nudity (merely implying it). It was after all, an exercise wholly in suggestion. Indeed, a search on YouTube, where the original adverts have been uploaded, shows that the early versions were far more suggestive than recent ones. But while the call to censor these adverts was succesful, their essential message has remained, and it does seem to resonate with the public, perhaps even pointing to a genuine truth about chocolate: for many, it is better than sex.

The actress Donna Evans in 1960s Flake advert.

In a list of the countries with the highest consumption of chocolate, Switzerland comes top, followed by Austria, Ireland, Germany and Norway. In fact, 16 of the 20 countries with the highest chocolate consumption are Northen European. (In America, chocolate is more popular as a flavour than as a bar, with more than half the population saying they preferred chocolate drinks, cakes, biscuits than any other flavour.) Given the reputation of chocolate as a substitute for sex, it is tempting to draw all sorts of cultural conclusions from this correlation. But there is another possible explanation for the high chocolate consumption in these countries, which is also associated with temperature. In order to transform from a solid to a liquid easily within the mouth, chocolate requires a fairly cool ambient temperature. In a climate that is too warm, chocolate will either melt on the shelf or need to be put in the fridge, which defeats the purpose entirely – cold chocolate gets swallowed before it’s had a chance to melt. (This problem may explain, perhaps, why the Meso-Americans, who first invented chocolate in the tropics, never created a solid bar but consumed in only as a drink.) Moreover if solid chocolate is exposed to temperature above 20°C, as a result perhaps of being left in the sun or in a hot car, it undergoes fundamental changes of structure. The changes can be spotted immediatelly because they result in “bloom”: fat and sugars migrate to the surface of the chocolate and form a whitish crystalline powder, often with a river mark pattern.

As well as pure pleasure, chocolate’s high sugar content and the perceived stimulating effects of the caffeine and theobromine have carved out another role for chocolate, encapsulated by the slogan “A Mars a day helps you work, rest and play” or it’s French equivalent: “Un coup de barre? Mars et ça repart!” (“Feeling beat? A Mars and you’re off again!); or its German one: “Nimm Mars, gib Gas” (“Take Mars, step on the gas”). With an average chocolate bar containing more than 50% sugar and 30% fat, it clearly offers a concentrated source of energy and an instant lift. For these same reasons, though, the healthiness of chocolate-rich diets has been called into question.

The 1st thing to note is that cocoa butter is a saturated fat, which is a class of fat associated with the increased risk of heart disease. Further investigation into how the body digests this fat has shown, however, that it tends to convert this fat into an unsaturated fat, which is thought to be benign. Meanwhile, the cocoa particles contain an enormous range of antioxidants, and no one really knows what they get up in the body. However controlled studies by Harvard University have shown that the regular consumption of a small amount of dark chocolate leads to an increased life expectancy (as compared to the consumption of no chocolate at all). No one knows why, and further studies are ongoing. Of course if the craving for chocolate becomes too much, any benefits will be offset by weight gain. At the moment, the jury is still out, but leaving aside over-consumption, chocolate is no longer seen as damaging to our health and perhaps even as beneficial. For all these reasons, although we are a long way from doctors prescribing chocolate or children being given it as part of a school diet, chocolate is an integral item in many countries’ standard military rations: it provides a sugar boost for energy, caffeine and theobromine for brain stimulation, and fats to replenish those lost during extreme exercise, and it has a shelf life of several years. Finally, but most controversially, it also may stave off feeling of sexual frustration.

Chocolate is one of our greatest engineering creations. It is certainly no less remarkable and techically sophisticated than concrete or steel. Through sheer ingenuity, we have found a way to turn an unpromising tropical rainforest nut that tastes revolting into a cold, dark, brittle solid designed for one purpose only: to melt in your mouth, flood your senses with warm, fragrant, bitter-sweet flavours and ignite the pleasure centres of the brain. Despite our scientific understanding, word or formulae are not enough to describe it. It is as close as we get, I would say, to a material poem, as complex and beautiful as a sonnet. Which is why the Linnaean name for the stuff, theobroma, is so appropiate. It means “the food of the gods”.

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