Tapioca is a food starch that is widely used in making puddings. It is taken from the root of the cassava, a tropical plant of the same fami- ly as the caster bean. Tapioca pudding is healthily and easily digested.
Commercial tapioca comes chiefly from Brazil, Java and the Malay Peninsula. A single plant may yield up to 10 pounds of starch. The roots are 2 to 8 inches and 1 to 4 feet long. They are washed to remove the prussic acid they contain, then reduced to a pulp. The pulp is strained until all the starchy particles are separated from the fiber roots. The starchy pellets are then set on hot plates to dry. The starch pellets form the small, uneven white balls known as pearl tapioca.
Pearl tapioca must be soaked in water for an hour before it can be cooked. A finer granular form, called quick cooking*, does not require soaking. Tapioca swells and thickens the liquid in which it is cooked. A flour made from cassava root is also used as a thickener. This flour is one of the starches called arrowroot.
References: The World Book Encyclopedia; World Book Inc.