 Many fermented teas do not arrive on the market ready for consumption.Instead, they may start as green teas or partially oxidized oolong-like teas, which are then allowed to slowly oxidize and undergo microbial fermentation over many years (comparable to wines that are sold to be aged in a cellar).Alternatively, fermented teas can be created quickly through a ripening process spanning several months, as with most Pu-erh.