Coffee tastes too sour
The cup tastes sharply sour or acidic rather than balanced, often alongside a thin body.
Applies to: Espresso machine, V60 (pour-over), AeroPress, Espresso, Filter coffee
Likely causes and adjustments
Try one adjustment at a time so you know what actually changed the result. Start with the first cause below — if it doesn't help, reveal the next.
Cause 1 of 3 · Commonly the cause
Under-extraction (not enough dissolved from the grounds)
Does the cup also taste thin, alongside the sourness?
Use a slightly finer grind, or increase contact/brew time.
Related issues
What to change
Specific adjustments for this symptom, with what each one trades off.
Work it out
Interactive tools that take you through this one change at a time.
Learn the technique
Step-by-step guides to the skills this problem comes from.
- Dialling in espressoFind the grind setting and recipe that make a particular coffee taste as intended, and be able to return to it.
- Adjusting grind sizeMove the grind in the right direction by a useful amount, and know what to expect from the change.
- Dialling in filter coffeeFind the grind and ratio that suit a particular coffee in a particular brewer, using brew time as the diagnostic.
- Blooming coffeeWet the whole coffee bed and let it release its carbon dioxide before the main pour begins.
- Preheating a brewerStop cold equipment taking heat out of the brew before it has finished extracting.
- Tasting coffee deliberatelyNotice what a coffee is actually doing, rather than only whether you like it.
- Measuring extraction yieldTurn a TDS reading into an extraction percentage, and know what that number can and cannot tell you.