Bitter espresso is a dial-in diagnosis, not a reason to give up. The usual culprit is over-extraction: too fine a grind, too much coffee, or too hot water.
This guide walks through the most common causes and exactly which lever to pull first.
Over-extraction basics
Bitterness and dryness signal you pulled too much dissolved material. Fix order: coarsen the grind a step, drop the dose 0.5-1g, or lower brew temperature.
A practical rule: if the shot runs too long (35s+) and tastes bitter, grind coarser.
Other culprits
Old or over-roasted beans (burnt flavours), a dirty portafilter, or too-high water temperature. Sometimes the "bitter" is actually burnt milk or scorched grounds.
Check your tamp is level — channeling can produce both bitter and sour notes in one shot.
The step-by-step fix
1) Coarsen grind slightly. 2) Re-pull and taste. 3) If still bitter, drop dose. 4) Lower temp if your machine allows. 5) Confirm beans are fresh and roast is reasonable. This sequence fixes most bitter shots.
