The main ingredient in the dessert treat known as tapioca pudding comes from the roots of a shrub that once grew only in Brazil. That shrub is the cassava, or manioc. The roots of this plant, which contain a great deal of starch, may be three feet long and weigh 30 pounds each.
To prepare the roots for cooking, they are first grated and soaked. This separates the starch from the rest of the root. Then the starch grains are spread over iron plates and exposed to heat.
This breaks them open. When they have cooled, they form small, hard pellets that are used to make tapioca pudding or to thicken soups. Another form of cassava starch appears in the spice racks as arrowroot.
Although tapioca is one of the most nourishing foods on earth, the most common form of cassava root is poisonous when raw, yet edible when cooked!