My pu-erh or dark tea tastes sour

In short

Sourness is the single most informative fault in dark tea, because it is the one that distinguishes a brewing problem from a storage problem from a manufacturing problem. In some teas it is intended and correct; in this category it almost never is, and where it comes from decides whether the tea is recoverable.

Likely causes, in order

Most likely first. Answer the question under each one before moving on — several of these look alike in the cup and are told apart only by what was done to the leaf.

1. 1. Too hot and too long on a young sheng

   Over-extraction

   Check: Is it a raw pu-erh under about five years old, brewed at a full boil with a steep of more than a few seconds?

   Fix: Young sheng is the most parameter-sensitive tea in common circulation, and pushed hard it goes sour and harsh together. Drop to around 90 °C, use a slightly lower dose, and keep the first several infusions to a handful of seconds. This is a brewing fault and it disappears completely when the brewing changes.

2. 2. A young shou whose pile has not rested

   Leaf quality

   Check: Is it a ripe pu-erh from the last year or two, and does the sourness sit alongside a pond-like note rather than replacing it?

   Fix: Fresh wet-piled tea carries both, and both fade over a few years in dry ventilated storage. Rinse it, brew it, and put it away for a year before deciding. This is a maturity question rather than a defect.

3. 3. Storage that was too wet, which is a different sourness

   StorageInferred by TeaHQ, not established

   Check: Has the tea been sealed in plastic, kept in a humid room, or bought from a seller who describes traditional wet storage? Does the sourness sit with a mustiness rather than with sweetness underneath?

   Fix: Wet storage that ran too far produces a sour, sharp cup rather than a smooth aged one. Move the tea somewhere dry, stable and ventilated and give it many months — sometimes years — before rejudging. Some of it recovers and some does not, and the smell of the dry cake tells you more about which than any single cup will.

4. 4. The rinse was skipped

   Technique

   Check: Did you drink the first infusion rather than discarding it?

   Fix: For compressed dark tea a rinse is standard rather than optional, and much of the sharpest surface character comes off in it. Pour boiling water over, discard immediately, then begin. A second rinse is reasonable on a tightly compressed cake.

5. 5. It is a lactic-fermented tea and the sourness is correct

   Leaf quality

   Check: Is this actually a Japanese goishicha, a Thai or Burmese fermented leaf, or another lactic-fermented product rather than a pu-erh?

   Fix: Those teas are made by lactic-acid fermentation and are supposed to be sour — it is the defining character, not a fault. The same word describes a defect in one category and the point of another, which is why identifying the category comes first.

Tea types this applies to

• Dark tea and pu-erh

Brewing methods this applies to

• Gongfu brewing (gaiwan) — A high-leaf, low-volume, many-infusions approach: a great deal of leaf in a small vessel, steeped for seconds at a time and poured off completely, repeatedly.
• Boiling aged and dark tea (zhu cha) — Compressed or aged dark tea put into a kettle of water and brought to a simmer rather than steeped. It is a normal winter preparation for Liu Bao, aged shou pu-erh, brick tea and tea nuggets, and it is also what a gongfu session’s exhausted leaf is for.

Related problems

Sharing a cause category, a tea type or a brewing method with this one.

• My pu-erh tastes exactly the same as when I bought it — A cake bought several years ago to age has not noticeably changed, and it was stored carefully.
• My gaiwan is too hot to hold — The rim and lid become uncomfortable within seconds, the pour is rushed, and tea ends up on the tray.
• My pu-erh cake will not break apart cleanly — The cake resists the pick, then gives way suddenly into powder and fragments rather than intact leaf.
• My shou pu-erh tastes fishy or muddy — A ripe pu-erh has a pond-like, fishy or muddy note that overwhelms everything else.
• Every infusion in my gongfu session tastes the same — The cups are pleasant and interchangeable, with none of the change from steep to steep the method is supposed to show.

Sources