People around the world eat about 7 million metric tons of chocolate every year. But chocolate isn’t just a sweet way to end a meal or a potential present for a loved one. It’s also a $128 billion annual business that offers a window into international commodity trading, colonial history, and the consumption habits of emerging markets.

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Why is West Africa the global capital of cocoa cultivation? How did small European countries become the premier producers of chocolate? And how do China and India fit into the picture? Those are a few of the questions that came up in my recent conversation with FP economics columnist Adam Tooze on the podcast we co-host, Ones and Tooze. What follows is an excerpt, edited for length and clarity.

For the full conversation, look for Ones and Tooze wherever you get your podcasts.

Cameron Abadi: Seventy percent of the world’s cocoa is now grown in West Africa, although it’s a crop that originates from South America. How did cocoa go from a crop that only grew in Central America to one that is primarily now grown in West Africa?

Adam Tooze: It’s a long and complicated story, and it’s not one that we can establish with real precision, because the origins of human cocoa culture are really to be found, we think, basically in the Mayan civilization, the traces of which were so comprehensively eradicated by European colonialism in the 1500s and 1600s. But no doubt it’s with the Mayans, really, that very high levels of cocoa civilization emerge. And it’s not an easy thing, right, because cocoa does grow on trees, but it’s not exactly obvious how you get to the cocoa that we know. Because you have to take the beans from inside the pods and then you have to dry them, which is a kind of fermentation process, and then you have to roast them, and then you can grind them up and you can make something delicious out of them.

But both Mayan and Aztec civilizations had very elaborate cocoa cultures, up to and including using cocoa beans as a form of currency and a form of tax payment and tribute payment. And through, then, the European colonial networks, this extraordinary bean spreads around the world within the Dutch Empire, it spreads to Indonesia. But it’s really the disintegration of notably the Portuguese Empire in the early 19th century, which brings it to where it will then establish itself as the main site of cultivation, which is West Africa. And it’s in the course of the 20th century that the overwhelming majority of commercial chocolate that people eat, you can assume it’s coming from Ghana or Côte d’Ivoire.

CA: So what is the supply chain like from cocoa farm to the final chocolate product that we buy in our supermarket? How many middlemen are there, exactly, along that supply chain?

AT: When we think about global supply chains, cocoa is arguably the most dramatic in its implications, because the cultivation of cocoa in West Africa, in Ghana and Côte d’Ivoire, is done by peasant farmers. It really is an instance in which something that shows up in your daily diet in the West is coming from a peasant producer in some of the poorest places in the world and with considerable amounts of child labor—though efforts are made by both the local governments and local communities and the managers of the global supply chain to contain that. Within those countries, it’s a three-step process, generally speaking. So you have peasants who sell to middlemen, who collect the beans in bags after the initial drying, and from there it’s then taken to national purchasing agents. The national purchasing bodies then go to the global market. And in the global market, they encounter what some people call grinder roasters. So these are not the chocolate firms that everyone knows, but the powerful powerhouse commodity companies, four or five of them who command the global trade. So they grind the cocoa—sometimes in situ—they roast, and then they ship out. And it’s those companies which then do the deals with the chocolate companies that everyone will know the names of: Mars; Mondelez, who own Kraft; Nestlé; Ferrero; Hershey’s. And then the final step in the chain is the retailers who buy the chocolate and distribute the chocolate from the major producers. So it’s six stages of a $130 billion industry, of which the original farmers maybe earn 6 percent of the revenue and 94 percent of it is distributed across this extraordinary extended chain.

CA: It’s small countries like Belgium and Switzerland that have the reputation as the premier chocolate producers in the world. Is that the product of colonial-era ties, or is this really more a matter of modern investments in chocolate production and modern marketing?

AT: The cocoa system globally is a legacy of the colonial settlement system, all the way back to the original Western encounter, disastrously, with Central American culture. So that has to be said upfront, because if you look at the history of Belgium and Switzerland, even in the Belgian case, it’s less obvious that their emergence as hubs of very high-end chocolate production in Europe is principally driven by colonial collection. And, in fact, many of the innovations in chocolate technology were more attributable at key moments in the early 19th century to French producers. Much of the commercial spread of chocolate is a British thing. Perhaps some of the key technologies for producing modern, smoothly edible chocolate bars come from Germany.

The emergence of Belgium and Switzerland as these major centers has got more to do with local innovation cultures and then clustering—you know, the same sort of clustering that we saw with perfume, for instance, where you get zones of expertise which are tied up with, for instance, in the Swiss case, the blending of chocolate with milk powder. That, for us, is a totally obvious thing to do, but it was, in fact, Swiss innovators in the 1830s that blended chocolate and milk for the first time to create milk chocolate.

And in the Belgium case, the emergence of Belgium in the 19th century as a chocolate center is, to a large extent, the result of migration from Switzerland—which was, at the time, still a relatively poor part of Europe—to Belgium, which was a very prosperous, rapidly industrializing part of Europe.

CA: How are patterns of chocolate consumption changing around the world? Do the Chinese like chocolate? How about in India?

AT: The world of chocolate consumption is hugely uneven. The absolute world champions of chocolate consumption are the Europeans, with the Swiss up around almost 10 kilos a year. It’s remarkable. The average for Europe is 7 kilos. America’s consumption is some way below that.

But the big question for the future is precisely the two countries that you’ve mentioned because of their size and their rapid economic growth, and they’re China and India. And they’re interesting, because they have very different dessert cultures. So Chinese dessert culture is not really centered on sweetness. There’s Chinese baking, of course, or Chinese ice cream, but you’ll know if you’ve tasted it that, in fact, it’s more about flavor than it is about pure sweetness. And so a milk chocolate culture, in particular, is not the most obvious thing for China to adopt. And that shows up in the data. So currently, compared to the 7 kilos that the Europeans eat on average, the Chinese manage 70 grams. So that’s, on average, per capita, a small chocolate bar per year for every Chinese person. So it’s one-hundredth of what the Europeans consume. So you can imagine how the big chocolate players globally regard this market as this vast opportunity for growth.

It may turn out that India is an easier sell. Because if anyone in the world has a sweet dessert culture, it’s definitely the Indians. They are the largest global consumers of sugar, in fact, in the world. But so far, chocolate is a relative novelty in Indian dessert and snack culture. Currently, their consumption is about 140 grams, so twice that of China, but still a long way short. And so if the European and American manufacturers could raise India or China to Japan’s level of consumption—Japan is the champion of chocolate consumption in Asia at 2 kilos per year—it would transform the entire business. It would add 2 billion consumers. And I think then the questions of equity in the supply chain would just become impossible to ignore, because you would be talking about a sector that, rather than puttering along at the level of inequality and exploitation, which, if we’re frank, we have just become sort of habituated to, you would need to understand, then, how on earth you would expand that system, because that’s what that kind of growth would require.