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