Chocolate was money before it was sweet

Before sugar arrived, cacao was a bitter drink. The Maya and the Aztecs ground the beans, mixed them with water, chilli, maize or vanilla, and poured the liquid from one vessel to another to raise the thick foam they prized so much. It was a ritual luxury, not an after-dinner treat.

And it was worth so much that it worked as currency. In the markets of pre-Hispanic Mexico you could pay in cacao beans: a few for an avocado or a tomato, more for a turkey. There were even counterfeiters who stuffed empty husks with clay to pass them off as coins.

It was the Europeans who added sugar and turned it into the sweet we know today. So chocolate made a curious journey: from bitter, sacred money to a supermarket bar. Few things have changed career quite so completely.