Why dark tea wants the hottest water
Dark tea wants the hottest water of any category, and it is not a matter of taste. The leaf is post fermented and usually compressed.
Compression is the main reason. A cake has been steamed and pressed, and it needs sustained heat over several steeps before it opens.
Post fermentation is the second. The compounds that give an aged dark tea its sweetness are held tightly, and they need boiling water to come out.
Water below 95 degrees gives you the storage smell and very little else, which is the usual reason people conclude a cake is poor.
There is no dark tea improved by cooler water. If you remember one thing from this section, make it that.
The contrast with green tea is worth stating plainly. There, cooler water protects the cup. Here, cooler water simply fails to produce one.
Temperature by dark-tea style
Ripe pu-erh wants a full boil, 8 grams in 200 millilitres, and 20 second steeps after the rinse.
Raw pu-erh also wants a boil, though young raw pu-erh can turn bitter with it. Keep the steeps short and it holds up.
Aged raw pu-erh is the most heat demanding of all. Use boiling water and expect it to improve through the sixth steep.
Fu brick and the other Hunan dark teas want a boil and do well simmered, which is how they are traditionally prepared.
Liu Bao and similar Guangxi dark teas are the same: boiling water, a rinse, and either short steeps or a long simmer.
With no information about a cake, treat it as ripe pu-erh and use a full boil. It is the safest default in the category.
Check what your kettle actually does. Many switch off below 100, and for dark tea that difference is the whole cup.
The rinse (awakening) step
A rinse is five to ten seconds of boiling water poured over the leaf and discarded. For compressed tea it is not optional.
It loosens the compression, so the first real steep is not spent on opening the leaf.
It warms the vessel and the leaf, which matters more here than anywhere else because of how much heat this leaf needs.
It washes off surface dust and the storage smell, both of which would otherwise end up in your first cup.
Old or tightly pressed cakes sometimes need two rinses, and the second one often still comes out dark. That is normal.
The rinse also tells you something. Water that smells musty or sour means the cake was stored badly, and no brewing will fix it.
Gongfu vs pot boiling
Gongfu with a small thick walled pot is the standard method, and it is the one to use when you want to taste the cake.
Boiling is the traditional alternative, and for an old cake it is often the better of the two.
Five grams in 600 millilitres, simmered gently for 10 minutes, topped up as the level drops. Keep it at a bare simmer rather than a rolling boil.
A thermos is the practical version for a working day. Five grams in 500 millilitres of boiling water, left for an hour, and it will carry a morning.
The weakest option is a Western pot with one five minute steep. It does not give a compressed leaf enough time to open.
Match the method to the tea rather than to habit. Old cakes suit boiling, and young ripe pu-erh suits a pot.
Whichever one you use, the water has to be at a full boil. That is the single rule in this category with no exceptions.
Practical takeaway
Use a full boil, every steep, without exception. Check that your kettle actually reaches 100 and does not cut off at 90.
Rinse the leaf first, and rinse it twice for an old or tightly pressed cake.
Use a heavy dose, 8 grams in 200 millilitres, and short steeps rather than one long one.
Keep the vessel hot between steeps. A thick walled pot or a small warmer makes a visible difference.
Judge the cake from the fourth steep. Almost every dark tea is worse at the start than in the middle.
Change one variable at a time when something is wrong. Temperature first, then dose, then steep length.