Espresso troubleshooting
One spout pours a pretty stream. The other dribbles. Before you throw away the shot or buy a new grinder, check whether you're looking at a spout problem—or a puck problem.
Two unequal streams do not prove channeling
A double-spout portafilter divides the coffee after it passes through the basket. Differences in spout geometry, residue, alignment or a tilted machine can affect the split. Unequal volume in the two cups does not tell you that one half of the puck was over-extracted and the other was under-extracted.
Check the simplest causes first
- Clean the spouts. Old coffee oils or residue can alter how liquid clings and exits.
- Check the setup. Put the machine and portafilter on a level surface; inspect the portafilter fit.
- Repeat with the same basket and dose. One odd-looking pour may not repeat.
- Weigh total output. Taste the shot and record dose, yield and time before judging the result.
When should you suspect puck preparation?
If the shot also tastes simultaneously sour and bitter, sprays through a bottomless basket, or varies dramatically between otherwise identical attempts, inspect grind consistency, distribution and tamp level. A bottomless portafilter can help you see some flow patterns, but it is a diagnostic tool rather than proof of a perfect or imperfect puck.
Symptoms and next steps
| What you see | Start here |
|---|---|
| One spout always drips | Clean and inspect the spout; check leveling |
| Both spouts run unexpectedly fast | Review grind, dose and basket fit |
| Bottomless basket sprays sideways | Revisit puck distribution and channeling |
| Output looks uneven but tastes good | Don't fix a problem you haven't measured |
A useful dial-in order
Set a repeatable dose and yield, make sure the puck is prepared evenly, then make small grind changes as needed. Keep the spout appearance as a secondary clue, not the final verdict.
An uneven split alone is not a diagnosis. Use our channeling troubleshooting guide to identify actual extraction problems, and consult how WDT can help distribute grounds if clumps or distribution appear to be involved.
One last reality check
If two cups need equal amounts for serving, weighing or combining and splitting after brewing can be more accurate than trusting two spouts to divide the shot evenly every time.
