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