Tapioca is a starchy ingredient derived from the tuberous roots of the tropical plant cassava (also known as manioc or yucca). It is most commonly formed into flour, round pellets (pearls), flakes or granules.

Tapioca pearls are small spheres typically 2 mm in diameter, although larger pellets up to 6 mm in diameter are also available. Most varieties need to be soaked for a few hours before being cooked, although some may be used without pre-soaking. The pearls are most commonly cooked in milk (and sometimes cream and eggs) to make tapioca pudding - a milky dessert similar to sago or rice pudding. The beads do not completely dissolve during the cooking process, resulting in a creamy mixture with gelatinous balls suspended throughout. Large pearls are also used to make a Taiwanese fruit or milk drink known as 'bubble tea' where the beads provide a chewy contrast to the sweetness of the drink. In India, boiled tapioca is normally eaten with fish curry or beef. When cooking pearl tapioca, it is important not to overcook it as it soon becomes starchy and sticky. When the beads turn translucent, they are fully cooked.
When ground into a flour, tapioca may be used as a thickening agent for soups, stews and sauces. It is a particularly good choice for thickening pie fillings, as it thickens at a lower temperature than many other thickeners such as cornflour, gives a glossy sheen, and remains stable when frozen.