How regions differ
Dark tea is made in four or five provinces, and each one ferments and shapes the leaf differently.
Yunnan is the largest, working from broad leaf assamica in Menghai, Mengku, Yiwu and Bulang.
Raw pu-erh there is pressed and left to change slowly, while ripe pu-erh is piled for weeks first.
Anhua in Hunan makes the fu brick, which is deliberately inoculated with jin hua（金花）.
Those golden spots are a controlled mould, and they give the tea a faintly fungal sweetness.
Anhua also produces the qian liang cha pole, compressed into a cylinder and dried in the open for months.
Liubao from Guangxi is basket aged, and mature examples develop the areca note the region is known for.
The material there is smaller leaf than Yunnan’s, and the finished tea is milder and less aggressive.
Sichuan and Hubei make compressed brick for the old trade routes, mostly from coarse leaf and stem.
Jingyang in Shaanxi once pressed Hunan material into fu brick, and the name is still used there.
So the category covers piling, inoculation and basket ageing, three quite different technologies.
Why the same tea diverges
Leaf type sets the first limit, and Yunnan’s broad leaf assamica carries more material for ageing.
It has more soluble sugar than small leaf, which is what the decades of change run on.
Small leaf material from Hunan or Guangxi ages more slowly, and it arrives somewhere softer.
The second divergence is the fermentation itself, which is not one process.
Piling for ripe pu-erh is a hot fast fermentation measured in weeks, driven by the heap’s own heat.
The jin hua in a fu brick is a slow fungal growth during a controlled sweating phase.
Basket ageing in Liubao is slower still, and it depends on the humidity of the storage room.
Compression changes the outcome again, since a tight brick sees almost no air and a loose basket does.
Shape is not cosmetic here, and it decides how fast the tea will move over the next 20 years.
Storage is the last variable and the largest, and it can ruin any of the regional work.
A Yunnan cake and a Guangxi basket kept in the same room at 70 per cent humidity diverge sharply.
Learning the signatures
Learn the three technologies by smell, since they are far more distinct than most regional claims.
Ripe pu-erh smells of damp earth and old wood when it is right, and of cellar when it is not.
A clean ripe tea has no sourness at all, and sourness means the pile was pushed too hard.
Fu brick smells faintly sweet and mushroomy, and the golden spots should be visible when it is broken.
Liubao at its best smells of areca and dried date, and it is smoother than either of the other two.
Brew 6 grams at 100°C and take it through 6 infusions, since dark tea is a long session drink.
Raw pu-erh from Yunnan is the most variable, and young examples are often harsh enough to be unpleasant.
That harshness is not a fault in a tea meant for 15 years, but it is one in a tea meant for now.
Look at the leaf after brewing, because large whole leaves point to Yunnan and chopped material to the bricks.
Stem content is normal in brick tea, and it signals the old trade standard rather than poor quality.
Taste two regions on the same afternoon and the difference is usually clear by the second infusion.
Tradition versus trend
Traditional dark tea was fuel for the frontier trade, and it was made cheap from coarse material.
The trend since 2000 has turned it into a collectible, and the collecting has driven most of the change.
Single mountain naming is the clearest example, since Bingdao and Yiwu refer to small and specific areas.
Demand has pushed those names onto tea grown elsewhere, which is routine at every price level.
Ancient tree claims follow the same pattern, and no label can be verified after the leaf is picked.
Anhua fu brick has had a quieter boom, helped by interest in the jin hua fermentation.
Machine pressing has largely replaced stone pressing, and the difference shows in how fast a cake matures.
A hydraulic press gives a tight cake that changes slowly, and a stone mould gives a loose one that moves.
Liubao has revived on the back of its own history, and old stock from the 1990s now sells well.
Ask where a cake was stored rather than where it was grown, since storage has overwritten origin by now.
The district tells you the technology, and the storage tells you whether that technology survived.