Pu-erh tea

„The process used to convert máochá into ripened pu'er is a recent invention that manipulates conditions to approximate the result of the aging process by prolonged bacterial and fungal fermentation in a warm humid environment under controlled conditions, a technique called Wò Dūi (渥堆, "wet piling" in English), which involves piling, dampening, and turning the tea leaves in a manner much akin to composting.“

„There is also a lack of formal definition for "gu shu." Some say "gu shu" should only refer to trees over 300 years of age, that is left to grow tall, and not pruned back. But in reality, most "gu shu" trees are cultivated, which entails annual pruning to encourage regrowth & lower branches for easy picking. A lot of "gu shu" on the market comes from trees as young as 100 years old, some of which is as short as 1.5m high. But a 100 year old tea tree growing in the wild can also grow higher than 3m high. Eventually the government will legislate what classifies as "gu shu." Until then, let the buyer beware!“