Foundational
Common coffee problems, at a glance
A starting point for diagnosing the most frequent brewing complaints, linking to detailed troubleshooting pages.
Start with taste, not equipment
Most brewing problems show up as one of a small number of taste complaints: too bitter, too sour, too weak, or an espresso shot running too fast or too slow. Identifying which of these applies narrows down the likely cause quickly — but each complaint typically has several plausible causes (extraction, water temperature, bean freshness, roast level and dose can all contribute), not a single fixed explanation, so the dedicated pages below list more than one thing to check.
Change one variable at a time
Grind size, dose, ratio, water temperature and contact time all interact. Changing more than one at once makes it hard to know what actually fixed (or worsened) the result.
Where to go next
See the dedicated troubleshooting pages for bitter, sour, weak, and fast- or slow-running espresso for specific causes and adjustments.