For most people, chocolate is purely tasty — but some of its history can be hard to swallow.

One reason to explore that history launched this week when chocolatier Jacques Torres opened a museum dedicated to the history of chocolate at his store in Manhattan’s SoHo neighborhood. Dubbed “Choco-Story,” the exhibit is the latest branch of chocolate museums curated by Belgian chocolatier Eddie Van Belle, who collected various pots, mortars and other materials that Mayans, Aztecs and 16th-century Spaniards used to make and serve hot chocolate before the industrial revolution, around the mid-19th century, led to the creation of a process by which chocolate could be turned into solid pieces. Though the exhibit hits the high points too, it doesn’t shy away from the most surprising tidbits about the dessert on display.

The first known use of cacao is believed to have been discovered in southern Ecuador near Palanda at Santa Ana La Florida in the region of Zamora Chinchipe, where 5,500-year-old ceramic pots and a piece of a mortar were found to contain traces of theobromine, a marker for cacao. Shamans among the Shuar Indians are said to have used this equipment to prepare hallucinogenic potions. At the first chocolate factories, workers crushed cacao beans by using a heavy cylindrical stone called a “mano” to crush the beans on a grinding stone known as a “metate,” equipment featured in the exhibit. A fire would be going underneath to soften the cacao to form a paste that, after being left to dry, was grated or diluted in water to make hot chocolate.

The cacao beans themselves, which also grew in the equatorial region of Veracruz and Mexico, were used as currency until 1737 (proof that money did grow on trees, at least in some parts of the world). “A turkey was 100 cacao beans,” says Cameron L. McNeil, author of Chocolate in Mesoamerica: A Cultural History of Cacao and an archaeologist at The Graduate Center at The City University of New York.

In the 14th century, only merchants, warriors, the nobility, and members of royal families could obtain cocoa drinks, and drank them out of golden cups and engraved or painted goblets.

According to the museum, after the Spanish colonized Mexico in the 16th century, they acquired the recipe for this hot chocolate and tried to keep it a secret from others. Jacques Torres says he believes it’s only logical that Hernán (or Hernando) Cortés — the Spanish conquistador who led the conquest of the Aztec kingdom — must have been the one who discovered this concoction and brought it back to the European continent. In a 1520 letter to Charles V, Cortés is believed to have described their currency as beans that are “somewhat like almonds” and to have said the natives caffeinated with the hot chocolate. Christopher Columbus is also said to have remarked on the trading of “almond-like” beans during his Fourth Voyage and after landing in what is now Nicaragua about two decades earlier, where he saw the beans and was greeted by the indigenous people with a bitter, spicy chocolate drink.

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However, historians say it’s hard to say that Cortés was definitely the first.

“Everyone assumes it was Cortés, but there was not functional proof of who brought it,” says Howard-Yana Shapiro, Chief Agricultural Officer of Mars, Incorporated, who co-wrote Chocolate: History, Culture with Louis Gravetti, an expert on the history of nutrition at UC Davis.

“He may have done so, but cacao is not in the inventory of goods that he took to show to Charles V,” echoes McNeil. She notes that The True History of Chocolate, by Sophie D. Coe and Michael D. Coe, traces the first evidence of cacao brought to the Spanish court to the friars who escorted Kekchi Maya to meet Prince Phillip. The friars would have had regular access to chocolate, she says, because many Mesoamericans continued their pre-conquest tradition of bringing cacao as a religious offering to places of worship. According to some sources, she says, “the friars would turn around and sell the offerings and make a lot of money doing this. They could also consume a certain amount of the offerings themselves. Let’s be honest, the friars were often as greedy as the conquistadors.”

Another reason to believe that clergymen rather than conquistadors brought chocolate across the ocean is timing. “By the time chocolate is coming back from New Spain or Mexico, the era of conquistadors was long gone,” says Marcy Norton, author of Sacred Gifts, Profane Pleasures: A History of Tobacco and Chocolate in the Atlantic World. Members of the clergy, however, were regularly making the transatlantic journey to build churches. “One of the things that facilitated its spread is that chocolate is very much a social practice, a feature of hospitality, something you offer friends and colleagues, so people got into the habit of offering it.”

Eventually, chocolate spread across Europe, perhaps thanks to Jewish traders who were expelled from Spain and ended up going to the Netherlands.

By around 1580, regular deliveries of cacao began to cross the ocean. (The exhibit also traces the first chocolate shop to Spain around the same time, but historians disagree on whether that one can be proved, too.) “You start seeing it in trade records in 1580s, the shipping of chocolate and its paraphernalia,” says Norton, who adds that any imports before then were more like souvenirs or samples. “The first time you see evidence of it being sold within Spain tends to be female vendors selling small amounts in stands in the street in places like Madrid in the 1630s.”

The royal families of Spain and France got the word out about cacao to various circles of the aristocracy in Europe, whether it was through marriages, hunting parties, diplomacy or jet-setting. In the mid-19th century, the removal of a tax on chocolate meant that everyone could benefit from what he believed were its nutritional benefits, and machines were developed that sped up the process of crushing the beans and that facilitated the production of solid chocolate pieces.

“Chocolate was the first stimulant beverage used in Europe,” says Norton. “It predates coffee or tea.” Think of it, she says, as “a gateway drug for coffee and tea.”

Write to Olivia B. Waxman at olivia.waxman@time.com.