On Food and Cooking

plant in the spurge family, Manihot esculenta,
which has the very useful habit of lasting in
the ground for as much as three years. It was
domesticated in northern South America, and
has spread through the lowland tropics of
Africa and Asia in the last century or so. It’s
often made into flatbreads or fermented as
well as cooked on its own. There are two
general groups of cassava varieties:
potentially toxic “bitter” varieties that are
used in the producing countries, and safer
“sweet” varieties that are exported and found
in our ethnic markets. Bitter varieties, which
are highly productive crop plants, have
defensive cells that generate bitter cyanide
throughout the root, and must be thoroughly
treated — for example, by shredding,
pressing, and washing — to become safe and
palatable. They’re mainly processed in the
producing countries into flour and tapioca,
small balls of dried cassava starch that
become pleasantly jelly-like when