Coffee tastes sour or bitter
Also searched as: sour coffee, bitter coffee, sour espresso
In short: Sour usually means too little was extracted, bitter too much: grind size, brewing time and water temperature decide.
Like a teabag taken out too early or too late: the good moment lies in between.
What happened in your kitchen?
Is the coffee more bitter than sour?
All causes, by frequency
3
- Ground too coarse or brewed too briefly
Acids dissolve first. If brewing stops too early, sweetness and body are missing and the acidity stands out.
Next time: Grind finer · Brew longer
- Ground too fine or brewed too long
The bitter compounds dissolve last. Too fine a grind or too long a contact time pulls them out.
Next time: Grind coarser · Brew for less time
- Water too cool or boiling
Below about 90 °C the water dissolves too little; water at a rolling boil quickly pulls out bitterness. About 92–96 °C works well (as a guide).
Next time: Use water just off the boil
Coffee and teaSources · 2
- Harold McGee: On Food and Cooking (2004), Kapitel Kaffee
- Specialty Coffee Association: Brewing Control Chart