Why does my coffee taste bitter?

Bitter usually means too much has been pulled out of the grounds: the grind is too fine, the water too hot, or the brew too long. The first change is one grind setting coarser.

Why does my coffee taste sour?

Sour usually means too little has been pulled out: the grind is too coarse, the water too cool, or the brew too short. The first change is one grind setting finer.

Why is my coffee weak?

Most often there is too little coffee for the water. About 1 gram of coffee for every 15 to 16 grams of water is a common starting point; then grind finer if it is still thin.

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☕ CoffeeLab Coffee Tool 2026 — Brew Troubleshooter

Coffee tastes wrong? Change one thing.

Bitter, sour, weak, harsh, muddy or flat: tell us how you brewed it and what changed, and get the one adjustment to make on the next cup — with the reason, in plain words.

4 questions One change per brew Every reason shown Rules, not guesses

Fix my coffee

Updated September 2026 · Published by CoffeeLabAdvisor

41 published rules·One change per brew·No score, ever·Updated September 2026

Every fix comes from a rule you can read, with the reason it should help. We have not tasted your cup, and no rule pretends we have. How troubleshooting works →

Answers stay in the address bar so a plan can be shared or bookmarked; nothing about you is stored.