At its heart, chai is a tea — specifically, a strong black tea. Forget those dusty tea bags you find in the back of the cupboard; good chai demands something with backbone, like a robust Assam or a malty Ceylon.
This isn’t a dainty, subtle brew. The tea leaves provide the caffeine kick and the deep, rich color that turns your milk a gorgeous caramel hue. Without this base, you’d just have fancy, spiced milk—and while that sounds nice, it wouldn’t be chai.