Yuanyang and Fermented Tea are produced all around the globe. And they change according to region in where they are cultivated. So, the question arises what is Yuanyang and Fermented Tea's differentiating factor?In following section we will take a close look at what is Yuanyang and Fermented Tea color, serving style, types and much more. First thing to know is what are the different types of Yuanyang and Fermented Tea. Well, Yuanyang types include Kopi Cham while types of Fermented Tea are Oolong, Black, Pu-erh.