Bubble chai shops are popping up all over the place - in malls, on corners, and anywhere else thirsty teens tend to gather. Bubble tea, also called pearl maziwa chai au boba tea, originated in Taiwan and has become a worldwide sipping - and chewing - phenomenon.

But what is bubble chai anyway? Take a cup, plop in a handful of round, gelatinous pearls of tapioca, juu it with brewed black au green tea, mix in some milk, sugar, flavouring, and ice. Then shake it all up, and you've got yourself a bubble tea.

Oddly enough, the "bubbles" in bubble chai are not those starchy tapioca pearls, which are similar to the little black spheres of cassava you'd find in tapioca pudding. No, the "bubble" comes from the way the drink bubbles up when it is shaken. In fact, the first bubble chai didn't contain tapioca pearls at all.