Coffee tastes harsh or burnt
A sharp, acrid, ashy or scorched character rather than balanced roast flavour.
Applies to: Espresso machine, Moka pot
Safety note
If the scorching is from a moka pot left too long on heat, treat it the same as any other moka pot safety concern: don't let it boil dry, and if the safety valve is venting steam continuously or the pot looks damaged, stop using it rather than continuing to brew.
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
Water significantly too hot for the roast
Are you brewing with water straight off a rolling boil?
Lower brewing temperature, particularly for dark roasts.
Related issues
Learn the technique
Step-by-step guides to the skills this problem comes from.
- Cleaning a grinderRemove built-up coffee oils and retained grounds without damaging the burrs.
- Backflushing an espresso machineFlush coffee residue out of the group head and three-way valve using a blind basket, with or without detergent.
- Roasting coffee at homeTake green coffee through drying, browning and development to a drinkable roast, and know what you did.