Puerh

Pu'er, or Pu-erh tea, is a variety of fermented tea traditionally produced in the Yunnan Province, China. In some places in the West, it has been marketed under the name red tea (in Chinese, 普洱茶; pinyin, pǔ'ěrchá) and its name comes from the Pu'er region.
Unlike other teas, which are usually consumed fresh after the harvest, the fermentation process of this variety of Camellia sinensis can last from 2 to 60 years, which causes the leaves to acquire a coppery color and, therefore, so does its infusion. There are often dates that indicate the different qualities of the harvests. Pu-erh tea can be purchased in loose leaf form or in pressed formats, such as compact balls, "cakes," "tea bricks," and other shapes that are broken down before preparation.