Ritter pulls cocoa from the obvious places: Africa and Central and South America, the hubs for cultivation. But no two beans are alike. Some are mild, some strong. Some are of average quality while others are much coveted by chocolate producers. Only about 5 percent of cacao harvested worldwide counts as so-called “fine cacao.” Ecuador, Colombia and Madagascar are among the producers. But the world leader is Papua New Guinea, which produces 90 percent of the world’s fine cacao, according to the museum.