<P> Tapioca balls are a product that comes from tapioca , a starch which is in turn extracted from the cassava root . They are also known as boba ( a transliteration of the word `` bubble '' ) or `` pearls '' in bubble tea . Some boba are five - to - ten - millimeter starch balls , consisting of sweet potato powder , potato powder , or jelly . By adding different ingredients -- water , sugar and seasoning -- tapioca balls can be made to vary in color and in texture . Tapioca balls are typically neutral in flavor and gel easily , making it often used as a thickening agent in foods like pudding . </P>
where do the bubbles in bubble tea come from
starch which is in turn extracted from the cassava root