Hearth & Bean

Troubleshooting

Why Is My Coffee Bitter? (And Sour?)

Bitter, sour, weak or muddy coffee usually comes down to grind size, water temperature, brew time or ratio. A fix for each.

Two small ceramic cups of coffee side by side on a wooden tray, with a ceramic pour-over dripper and a speckled kettle out of focus behind.

Most bad cups of coffee come from one of four things: grind size, brew time, water temperature and ratio. If you can tell whether the cup is sour or bitter, you can usually fix it in one step.

Quick diagnosis

What you taste Likely cause What to try
Sour, sharp, thin Under-extracted: water didn't pull enough out of the coffee Grind finer, brew a bit longer, or use hotter water
Bitter, harsh, dry Over-extracted: water pulled out too much Grind coarser, shorten the brew, or let the water cool slightly
Weak Too little coffee for the water Use more coffee
Muddy or gritty Grind too fine for a metal filter, or stale beans Grind coarser for French press, pour slowly
Flat or papery Stale beans or old pre-ground coffee Buy fresher beans and grind just before brewing
Sour, balanced and bitter coffee on one scaleA scale from under-extracted and sour on the left, through balanced in the middle, to over-extracted and bitter on the right. If sour, grind finer, brew longer or use hotter water. If bitter, grind coarser, brew shorter or use slightly cooler water. How much the water pulled out of the coffee Under-extractedSour, sharp, thin BalancedSweet, smooth Over-extractedBitter, harsh, dry If sour, trygrind finer, brew longer,use hotter water If bitter, trygrind coarser, brew shorter,use slightly cooler water
Change one thing at a time, then taste again.

Step by step

  1. Check the grind first. It has the biggest effect. Sour? Go a little finer. Bitter? Go a little coarser.
  2. Check the ratio. See our coffee to water ratio chart.
  3. Check the water. Just off the boil (about 195 to 205 °F) suits most brewers. Water that is far too cool tends to taste sour.
  4. Check the time. Pour-over is usually done in 2½ to 3½ minutes, and French press in about 4.
  5. Check freshness. Coffee tastes best within a few weeks of roasting. Store it in a sealed container away from light and heat.

Moka pot specific

A bitter moka pot is usually left on the heat too long or on too high a flame. Use medium-low heat and take it off as soon as it begins to sputter. Running it under cold water for a moment stops the brewing.

Change one thing at a time

Adjust only one variable per cup and write down what you changed. Two or three adjustments is usually enough to find a cup you like.

Try it at home

Gear that fits

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