Pu-erh

Pu-erh is unique among teas for its microbial transformation, which continues to develop flavor over years and even decades. Two categories exist: sheng (raw) pu-erh, which ages naturally and evolves from bitter-astringent to smooth and complex; and shu (ripe) pu-erh, which undergoes accelerated fermentation (wo dui) over 45-60 days to simulate aged character. The tea is typically compressed into cakes (bing), bricks (zhuan), or tuocha (bird's nest shapes) for storage and aging. Only tea made from large-leaf Yunnan varietals processed in designated Yunnan production areas can legally bear the pu-erh designation. Fine aged sheng pu-erh is among the most collectible and expensive teas in the world, with vintage cakes from the 1950s-1990s commanding thousands of dollars.