Every chocolate bar and cup of marshmellow-garnished goodness starts with a cocoa tree, Theobroma cacao. The glossy green leaves shelter foot-ball shaped pods that sprout directly from the tree’s trunk and hold the beans to be ground into cocoa.
The trees are native to Central and South America, but our demand for chocolate has driven production all around the tropical world, including to West Africa and Southeastern Asia. Sometimes that means that one plant needs to move from country to country. And that trip requires a stop-over in Britain, at the International Cocoa Quarantine Centre, reports Ari Shapiro for NPR.
Out in the British countryside, the center includes banks of greenhouses that offer the swampy tropical feel the cocoa tree needs to thrive. About 400 varieties are housed there, all as a safeguard against the many diseases that threaten cocoa. NPR reports:
Every year, a third of the crop is destroyed by fungi and pests with names like "Witches' Broom," "Frosty Pod Rot," and "Vascular-streak dieback."
A few years ago, one of these cocoa diseases hit Brazil. At the time, "Brazil was one of the world's largest cocoa-producing countries," says Laurent Pipitone of the International Cocoa Organization in London. "When this new disease came, it reduced their production by about half."
Research on varieties to resist those rots and streaks happens around the world. Any new variety is a chance for growers to improve their yield, so cuttings from those new trees are in demand. But those cuttings can harbor disease and potentially spread it around the world. Instead, the center intercepts the exchange, checks the plant for any pests or diseases, takes cuttings to be held in research institutions and then passes it on.
The current quarantine process can take two years of observation, though the center writes that new technologies should help accelerate that timeline. If the idea of greenhouses full of potentially disease-laden plants worries you, you’ve forgotten something: The center was deliberately built in the U.K., "a place with weather so dreary, none of those awful cocoa diseases could possibly survive outdoors," NPR reports.