Cassava

Cassava is one of the most important foods almost no one in the rich world thinks about. Known also as manioc, yuca, and tapioca, it is a starchy tuberous root that feeds an estimated 800 million people and is, after rice and maize, one of the leading sources of calories in the tropics. World production runs about 340 million tonnes of fresh roots a year, and roughly 65 percent of it grows in Africa, where Nigeria alone produces around 60 million tonnes, the most of any country, followed by the Democratic Republic of Congo and, in Asia, Thailand.

Its great virtue is toughness. Cassava grows in poor, acidic soils and shrugs off drought that would kill maize, and its roots can be left in the ground for months as a living store of food until they are needed, which makes it a famine insurance crop across the tropics. Its great danger is chemical: the roots contain cyanogenic glucosides that release cyanide, so cassava must be processed, soaked, fermented, pressed, and dried, before it is safe to eat, and the highest-yielding "bitter" varieties are the most toxic. That processing gives African kitchens gari and fufu and Latin American ones tapioca and farinha.

The plant is an American native, domesticated in the Amazon basin of Brazil thousands of years ago, and it is one of the great crops carried out of the New World by the Columbian Exchange. Portuguese traders took it to Africa and Asia in the sixteenth century, teaching the detoxifying techniques along with the plant, and it took hold so completely that Africa is now both the largest producer and the largest consumer, and cassava reads to most people as an African rather than a South American staple.

Cassava has no futures market and is unlikely ever to have one. Most of the crop is eaten close to where it grows, fresh roots are heavy, perishable, and low-value, and only the processed forms, dried chips and pellets for animal feed and starch for food and industry, travel far. What international trade exists runs overwhelmingly out of Thailand, the world's dominant exporter with roughly 60 percent of the global trade, and into China, which buys Thai cassava chips and starch for animal feed, sweeteners, and ethanol and accounts for the largest share of world imports. Prices are set physically, quoted by the Thai trade for chips and starch, with no exchange contract, no forward curve, and no speculative market.