What to look at
Dark tea is judged on cleanliness first and character second, and that order matters.
Start with the dry leaf. Ripe tea should be dark and evenly coloured, with no grey or white patches.
The dry smell should be earthy and slightly sweet, like wet leaves or old wood.
A fishy or sour smell means the fermentation ran badly, and it is the most important fault to catch.
For raw tea the dry leaf is lighter and greener, and it smells sharp and slightly bitter when young.
The liquor should be clear: deep red-brown for ripe tea, and yellow to orange for a young raw tea.
Cloudiness in a ripe tea is normal in the first rinse and should clear by the second pour.
On the palate, look for sweetness and thickness, and watch for any drying or sour finish.
The wet leaf should be soft and pliable. Leaf that has turned to sludge means the material was poor to begin with.
A standard cake weighs 357 grams, which at 7 grams a session is about 50 sessions from one purchase.
The order of inspection
Inspect a cake before you brew it, which is the one thing about this category that is genuinely different.
Look at the wrapper first: factory, recipe number, year. Three marks is a good start.
Then the cake surface, which should be even and not pressed so hard that it will not break.
Break a piece and look at the interior. It should match the surface, and the smell at the break is the truth.
Rinse once with boiling water, discard it, and smell the hot wet leaf in the pot.
Brew at around 7 grams per 150ml, and judge the first three pours rather than only the first one.
Look at the liquor for clarity and colour before tasting, and check whether it clears after the rinse.
Taste for sweetness and body, then wait. A good dark tea leaves a sweet finish that lasts.
Finish with the wet leaf, spread out. Soft and whole is right, and fragmented and slimy is not.
Ripe tea takes a full boil and a long steep. Raw tea brewed the same way will be undrinkable.
Red flags
The faults in dark tea are nearly all about fermentation and storage, and they are not subtle once you know them.
A fishy smell on the wet leaf is the classic sign of a bad pile fermentation, and nothing fixes it.
A sour note means the pile ran too wet or too hot, and it reads as sour in the cup as well.
Mustiness means damp storage, and it is the commonest fault in privately stored cakes.
A dull, muddy liquor that never clears is a bad sign for both the material and the storage.
A flat taste with no sweetness and a drying finish means the tea has nothing left to give.
Unmarked cakes, no year, and a story about a warehouse find are three flags that travel together.
Ripe tea sold as decades old is the standard lie, since the process was only standardised in the 1970s.
Two flags and you should be looking at something else, and at this price there is always something else.
Ripe tea was standardised in the 1970s, so a cake sold as fifty years old is either lying or mislabelled.
Keep a baseline
Your reference here should be a ripe cake from a known factory, bought young, from a shop you trust.
Drink it over six months and pay attention to what a clean fermentation tastes like.
That baseline tells you more than any description of what a good ripe tea should be.
Buy three of the same cake if you can afford it: one to drink, one to keep, one to compare later.
For raw tea, find someone with an aged cake and drink it before you buy anything to age yourself.
Young raw tea is not a good reference for anything, because it is not finished.
Write down the factory, recipe, year and price for every cake, plus one line about the smell.
Open one cake a year from the oldest you have, and compare it with the same tea bought fresh.
Ten years of that habit is what an educated palate in this category actually consists of.
Three cakes of one recipe, opened at two, five and ten years, teach more than fifty bought singly.