What's the difference between pre-fermented and post-fermented Pu'er tea? The question we got asked most often from the new Pu'er tea drinkers. What made Pu'er special is that its flavour is changing over time, just like red wine. Time will bring back the magic of nature, and the flavour of Pu'er tea is gradually getting a richer aroma and mellow taste. And that leads us to the concept of "pre-fermented tea" (Sheng) and "post-fermented tea" (Shu) according to its making process and taste.