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.“

„Depending on the desired product and speed, from quickest and tightest to slowest and loosest, pressing can be done by a large heavy stone, carved into the shape of a short cylinder with a handle, simply weighs a bag of tea down onto a wooden board. The tension from the bag and the weight of the stone together give the tea its rounded and sometimes non-uniformed edge. Due to the manual labor involved, this method of pressing is often referred to as: "hand" or "stone-pressing", and is how many artisanal pu'er bǐng are still manufactured.“