Among the six great families of Chinese tea, dark tea—hei cha—remains the least exported yet most storied. Within this shadowed realm, Fu brick tea from Hunan province stands as both sentinel and ambassador: a compressed brick whose internal alchemy produces a galaxy of tiny golden specks nicknamed “golden flowers” (Eurotium cristatum). For fourteen centuries, caravans measured the distance between Chang’an and Kashgar by the slow maturation of these bricks, and today the same tea is courted by collectors who prize its medicinal mellowness and its ability to improve, like vintage wine, for decades.
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From Frontier Necessity to Imperial Tribute
The genesis of Fu brick is inseparable from the geopolitics of tea and horses. During the Tang dynasty (618-907), border markets exchanged Sichuan and Hunan tea for Tibetan warhorses. Compressed into hard bricks, the tea survived yak-caravans across the Qinghai-Tibet plateau without molding. By the Ming (1368-1644), the imperial court institutionalized the “Tea and Horse Bureau,” stipulating that only Hunan’s Anhua dark rough tea (Daye zhong cultivar) could be pressed into official bricks. The name “Fu” itself first appears in 1644, when a factory in Jingyang county, Shaanxi, was licensed to produce bricks for the western garrisons; locals pronounced the character 茯 (fu) like “fu” (blessing), and the auspicious homonym stuck. Qing-era merchants discovered that bricks accidentally stored in humid summer warehouses developed a yellow bloom that mellowed the originally harsh tea; instead of discarding the “spoiled” cargo, they marketed it as “golden-flower Fu brick,” fetching three times the price of ordinary dark tea. Thus, a microbial accident became a controlled art, and by 1860 Fu brick was listed among the eight tribute teas presented to the Dowager Empress Cixi. -
Terroir and Leaf: The Anhua Advantage
Authentic Fu brick begins in the fog-locked gorges of Anhua county, Hunan, where the Zi River cuts granite mountains into a labyrinth of microclimates. The native Daye zhong tea tree is a large-leaf landrace that accumulates unusually high levels of flavonoids and pectin, the very substrates that Eurotium cristatum will later transform into aromatic polyketides. Spring picking follows the “one bud with four leaves” standard; the fourth leaf, coarse and waxy, is essential because its thickness allows the leaf to survive the forthcoming steam-softening without disintegrating. Within six hours of plucking, the leaves must reach the primary factory in Dongping village, where humidity hovers at 78 %—a timing that local truck drivers still observe with almost spiritual urgency. -
Crafting the Brick: A 29-Day Fermentation Symphony
Fu brick production is a choreography of moisture, heat, and oxygen that makes oolong oxidation look elementary. The sequence, unchanged since 1875, is divided into four acts:
a) Fixing & Rolling: A 280 °C drum roaster kills green enzymes in 90 seconds; the leaves are then rolled under 55 kg granite rollers for 40 minutes to rupture 65 % of cell walls while preserving stem integrity.
b) Piling: The damp leaves are heaped 1.2 m high in pine-lined rooms where temperature is allowed to rise to 55 °C over 24 hours. This “wet piling” stage, shared with shou Pu-erh, lasts 8 days and cultivates a mixed microbial community dominated by Aspergillus niger and yeasts.
c) Brick-forming & Inoculation: The semi-fermented maocha is steamed for 8 seconds—just long enough to raise moisture to 22 %—then packed into fir molds measuring 35 × 18 × 5 cm. A powdered starter culture of Eurotium cristatum spores, conserved from the previous batch, is dusted between every 200 g layer. A 28-ton hydraulic press compresses the tea to a density of 1.1 g/cm³, tight enough to retard aerobic molds yet loose enough to allow micro-oxygenation.
d) Flowering & Drying: The bricks are stacked in an underground “flower room” kept at 28 °C and 75 % RH. Over the