Tapioca balls

Tapioca balls come from tapioca, which is a starch extracted from the cassava root (also known as yuca in some parts of the world). It is used as a thickening agent in many foods. It can be made into flour — it has a similar texture to cornstarch — which is often times used in gluten-free breads. It can also be made into pearls in varying sizes, which 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 has a neutral flavor and strong gelling power, making it highly usable as a thickening agent in both sweet and savory foods. Unlike cornstarch, tapioca can withstand a freeze-thaw cycle without losing its gel structure or breaking down. Tapioca must be soaked and then boiled with a liquid to form a gel and is therefore usually added to food prior to cooking. To make the tapioca pearls, the moist cassava starch is passed through a sieve. Once dry, it’s then rolled up into little balls. Depending on the ingredients of the pearl, the color varies. Tapioca pearls that are white contain just the cassava root. The brown ones contain cassava root, brown sugar and/or caramel coloring. The little starchy brown spheres are plopped into hot water, sometimes with even more added sugar, to cook for no longer than three hours. When boba are overcooked, they can be really mushy and when undercooked the pearls can be crispy or hard. Boba should be smooth and soft on the outside and have a consistency between gummy bears and Swedish fish on the inside. To make it extra chewy (or “QQ”), the boba are chilled quickly after cooking.

In Taiwan, it is more common for people to refer to bubble tea as pearl milk tea (zhēn zhū nǎi chá, 珍珠奶茶) because originally small 1/12” tapioca pearls were used. It was only when one tea shop owner—in an attempt to make his tea stand out—decided to use larger tapioca balls and chose a more provocative name, “boba,” to represent the difference. In Chinese, the word boba, 波霸, is a combination of a word for bubble and a word for big, which, when found together, is slang for “big breasts” or “buxom lady.” When used to describe the drink, the characters 波霸奶茶 directly translate to boba milk tea, and loosely to bubble milk tea. This translation is commonly used by English speakers and refers to the variant with 1/4" tapioca pearls.

...
Wikipedia