Doppio and Black Eye Coffee 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 Eye Coffee's differentiating factor?In following section we will take a close look at what is Doppio and Black Eye Coffee color, serving style, types and much more. First thing to know is what are the different types of Doppio and Black Eye Coffee. Well, Doppio types include Espresso while types of Black Eye Coffee are NA.