Doppio and Liqueur 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 Liqueur Coffee's differentiating factor?In following section we will take a close look at what is Doppio and Liqueur Coffee color, serving style, types and much more. First thing to know is what are the different types of Doppio and Liqueur Coffee. Well, Doppio types include Espresso while types of Liqueur Coffee are Whisky Coffee, Gaelic Coffee, Irish Cream Coffee, Sultan Special Coffee, French Coffee, Brandy Coffee, German Coffee, Italian Classico, Caffe Corretto, English Coffee, Russian Coffee, American Coffee.