The method
Dark tea is reviewed differently from every other category, because age and storage are part of the tea.
A raw pu-erh and a ripe pu-erh from the same year are not two versions of the same thing.
Set the method first, and 7 grams of leaf to 120ml of water at a full boil is the common standard.
Rinse the leaf once for about 5 seconds, which wakes compressed material up and washes off storage.
Keep the leaf weight and water volume fixed across samples, or the comparison tells you nothing useful.
Smell the wet leaf after the rinse, then smell the empty cup after every second infusion.
Storage smell appears in the wet leaf first, long before it shows up in the liquor at all.
Keep a reference sample, ideally one cake you have followed for years, and brew it every single time.
Describe first and judge afterwards, because dark tea rewards patience and punishes quick conclusions.
Taste the same cake across three sessions on different days before writing anything final about it.
Setting up
Use fully boiling water, since dark tea is made for heat and gives very little below about 95°C.
Soft water is best, although this category tolerates harder water better than white or green tea does.
A 100 to 150ml gaiwan or a small clay pot both work, and you should keep the same one all session.
Weigh the leaf rather than estimating, because compressed material is very easy to over-portion.
Rinse once for 5 seconds and discard it, and for cakes older than fifteen years many tasters rinse twice.
Steep 15 to 20 seconds for the first few infusions, then extend as the flavour begins to drop.
Expect 10 to 15 infusions from good material, because that endurance is itself part of the score.
Sample from several places in the cake, since the surface and the core have not aged at the same rate.
Ventilate the room and keep the wet leaf in a separate bowl, so its smell does not sit under your nose.
Three samples is the limit, since dark tea is thick and after four everything tastes like the one before.
What to score
Look at the dry leaf for the grade: how many buds, how much stem, whether the compression is even.
Ripe pu-erh should be dark and even, while raw pu-erh changes colour with age from greenish to brown.
Smell for fermentation character first and for storage second, since the two differ and both are legitimate.
A clean ripe tea smells of damp earth and old wood, and a fresh pile smell, or dui wei（堆味）, fades in a year or two.
Mould is not the same as age, and a musty sharp smell clinging to the empty cup is simply damage.
Judge the liquor for darkness and clarity, because it should be clear at any age and never cloudy.
Taste for thickness first, then for sweetness, then for the length of the finish.
Bitterness in young raw pu-erh is normal, but it should turn sweet rather than scrape the throat.
The finish is the best indicator of quality here, since good material leaves sweetness and a cooling feel.
Inspect the spent leaf, which should be soft and pliable rather than hard, brittle or slimy.
Avoiding bias
Age, region and price are louder in dark tea than anywhere else, and all three distort the tasting.
Take the wrapper off, number the cups, and do not say what anything is until the notes are written.
Brew raw before ripe and younger before older, or the heavier teas will erase the lighter ones.
Rinse your mouth well between samples, and leave a full minute before the next cake comes up.
Use separate pots for raw and ripe if you have them, since ripe tea leaves a smell that lingers for days.
Review early in the day, because dark tea is filling and it flattens your appetite and palate with it.
Do not score the first infusion, which is usually thin or dominated by whatever the rinse left behind.
Have a second person pour and number the samples, so that nobody at the table knows which is which.
Re-brew anything you ranked first or last, since those are the two positions most often wrong.
Watch how a tea changes across infusions, because a cake flat by the fifth has less material than it claims.