Doppio and Black Tea are produced all around the globe. And they change according to region in where they are cultivated. So, the question arises what is Doppio and Black Tea's differentiating factor?In following section we will take a close look at what is Doppio and Black Tea color, serving style, types and much more. First thing to know is what are the different types of Doppio and Black Tea. Well, Doppio types include Espresso while types of Black Tea are Tanyang Gongfu, Zhenghe Gongfu, Zhengshan xiaozhong, Earl Grey Tea.