Keemun, Qi Men Red Tea, from a former county of Keemun in Anhui Province, was once the popular "English Breakfast Tea". It is the best known of the north China Congous. There are various grades of Keemun such as Mao Feng, Hao-Ya, and Ji Hong. Keemun contains a substance called myrcenal. This is an essential oil that is unique only to the variety of tea plant from which Keemun tea is produced and which gives it a distinctive taste. It is said that it has a flavor that almost sings!