Shou puerh (also written as 'shu') is translated as 'ripe' (dark) puerh. With the increase of popularity of puerh tea, researchers started experimenting in the 1960's on how to speed up the natural aging process. A lot of inspiration was driven from traditional Chinese black tea (hei cha) such as Liu Bao and a a quickened method of fermentation (wo dui) was developed to make the tea ripe and dark, soft and mellow to drink directly after processing, as opposed to the naturally fermented (sheng) puerh that needs to age for several decades before reaching similar state of ripeness. A new category of tea was born... Undoubtedly a very special and unique type of tea with a growing number of admirers!