Common failure modes

Common Failure Modes

• Channelling:

• Water finds weak paths through the puck.

• Signs: spurting, uneven flow, blonding early.

• Fixes: improve puck prep (distribution, tamp), ensure even grind.

• Under-Extraction:

• Sour, sharp, thin body.

• Causes: grind too coarse, too short time, too low dose or temperature.

• Fixes: grind finer, lengthen time, raise temperature.

• Over-Extraction:

• Bitter, hollow, astringent.

• Causes: grind too fine, long shot time, excessive yield.

• Fixes: grind coarser, shorten shot, reduce yield.

• Channel Collapse / Puck Fracture:

• Uneven tamp or basket overfilling causes puck to crack under pressure.

• Signs: gushing or uneven blonding.

• Fixes: correct dosing, level tamping, avoid knocking portafilter.

• Temperature Instability:

• Inconsistent flavor between shots.

• Causes: machine not fully warmed, poor PID control, cooling flushes neglected.

• Fixes: stabilize grouphead, follow warm-up protocols.

• Grinder Retention or Inconsistency:

• Old grounds mixing with fresh ones → inconsistent shots.

• Fixes: purge grinder, single-dose workflow, maintain burrs.

• Dirty Equipment:

• Oils and fines build up in baskets or shower screens.

• Causes rancid, bitter, or ashy flavors.

• Fixes: regular backflushing, basket cleaning, detergent use.

Summary

Espresso failure modes include channelling, under- or over-extraction, puck collapse, temperature swings, grinder issues, and dirty equipment. Recognizing signs quickly and applying targeted corrections ensures consistently balanced espresso.

• Tags:
• Oils Fines
• Puck Prep
• Summary Espresso
• Inconsistent Flavor
• Uneven Flow
• Grind Finer
• Old Grounds
• Balanced Espresso
• Extraction Sour
• Pid Control
• Grind Coarser
• Reduce Yield
• Bitter Hollow