Channeling
Water finds weak spots in the puck, causing uneven extraction with spurts or side streams
What This Looks Like
Compare your shot to these visual cues to confirm the symptom.
Extraction flow
Crema color & texture
Cup appearance
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Quick Diagnosis
Do you use a distribution technique before tamping?
For a more thorough diagnosis, try our full diagnostic tool.
Possible Causes
Uneven Puck Distribution
3 solutions available
Coffee grounds are unevenly distributed in the basket, causing channeling
Inconsistent Tamping
2 solutions available
Uneven or tilted tamping creates weak spots in the coffee bed
Grind Too Coarse
3 solutions available
Coffee particles are too large, allowing water to pass through too quickly
Dose Too High
2 solutions available
Too much coffee in the basket, potentially touching the shower screen
Stale Coffee Beans
2 solutions available
Coffee beans are past their peak freshness, having lost flavor and CO2
Recommended Solutions
Use WDT Tool for Distribution
Use a WDT (Weiss Distribution Technique) tool to break up clumps and evenly distribute grounds in your portafilter before tamping.
Expected Result
Eliminated channeling, more even extraction, consistent shot times.
Ensure Level Tamping
Apply even, level pressure when tamping. Use a leveling tamper or practice keeping your wrist straight and elbow at 90 degrees.
Expected Result
Even extraction across the puck, eliminated side channeling, consistent flavor.
Use Precision Filter Basket
Replace your stock filter basket with a precision basket like VST, IMS, or Pullman. These have more consistent hole sizes.
Expected Result
More even extraction, better flow, reduced channeling potential.
Grind Finer
Adjust your grinder to produce finer coffee particles. Make small adjustments (2-3 increments on most grinders) and pull a test shot.
Expected Result
Extraction time should increase by 3-5 seconds. Flavor should become more balanced with less sourness.