Two of the world's largest chocolate makers, Mars Inc. and Barry Callebaut AG, say the world is running out of chocolate, due to drought, disease, and displacement of cacao—the raw material behind the sweet stuff—by crops such as corn and rubber. Trying to make up the shortfall, farmers in Central America and South America are investing in new strains of cacao. One is a breed called CCN51, renowned because it produces nearly seven times more beans than its traditional Ecuadorian counterpart. The drawback: it is bitter and tastes like "acidic dirt," according to one profiler. Luckily, other strains being pursued—called R-1, R-4, and R-6—are said to taste really good. R-6 has even been commended for its "nutty and woody notes, with undertones of brown fruit." With any luck, the new strains will forestall the chocolate deficits projected by 2020.