Tazo is the brand Chai they use, as stated before.
I have found a (one liter?/ Half gallon?) box of liquid Tazo chai...the same one you can buy off the counter in SB.
If you mix equal parts Chai and milk you get a pretty similar taste in the microwave. It isnt quite as sweet and teher is something missing....thats actually why i came looking! But its still good and the whole box is about the price of one Grande. If you buy the box mix at a supermarket that is not in the SB store