A specific over-extraction symptom where the cup loses clarity and tastes thick, dull, and undifferentiated. Acidity collapses, the aromatics that should be sitting on top go quiet, and what's left is heavy roast and cardboard. The bean stops sounding like itself.
The word comes from how the cup feels in the mouth and looks in the glass — opaque, sediment-y, less alive than the same coffee correctly extracted. A muddied V60 reads almost like a bad French press.
What causes it
Three usual suspects, often combined:
- Grind too fine for the contact time. Fines extract faster than the bed average, dragging in bitter and astringent compounds.
- Stalled drawdown. When the bed plugs and water sits stagnant, late-extracting compounds keep extracting past the sweet point.
- Too much agitation. Aggressive stirring or heavy late pours bring fines to the surface and break up the bed structure that filters them.
How to fix it
Coarsen the grind one notch first. If drawdown is the problem (you can hear it: water just sitting there past the expected finish time), grind coarser still. If the recipe is sound but you're getting muddied cups on Hario V60s specifically, the paper filter may be the culprit — Hario tabbed filters from cheaper packs run slower than the official Hario VCF. Switch to the white tabbed filters, brew again, decide.