Clear tapioca pearls have the most versatility in the kitchen where they're used as a thickening agent and for classic tapioca pudding. Black tapioca pearls, or boba, which get their color from brown sugar, are almost exclusively used in bubble tea because of their color and sweetness. Both come from cassava root and need to be simmered in 2 cups of water for every 1/4 cup of pearls.
You find tapioca pearls used as thickening agents in soups and sauces that benefit from a glossy sheen, and sometimes pie fillings. Soak clear tapioca pearls in water overnight before using them as a thickener or for pudding.
To make bubble tea, simmer black tapioca pearls until they float, about 12 to 15 minutes, then let them steep another 12 to 15 minutes. Mix together equal parts hot water and sugar together and stir to dissolve the sugar. Pour this over the hot boba and chill it in the refrigerator overnight. Add the crystallized boba to chilled flavored tea the next day.