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A moka pot that will not brew, or sputters violently instead of streaming, has a pressure problem you can see with your hands: too little resistance (coarse grind, underfilled basket, worn gasket) makes it spit and blast; too much resistance (fine grind, tamped basket, clogged filter plate) makes it strain, hiss at the safety valve, and deliver nothing. The pot is a pressure gauge you drink from, and every fix below is about putting the resistance back in the middle.
Symptom to cause
| Symptom | Cause | Fix |
|---|---|---|
| Violent sputter, fast blast | Too little resistance | Grind slightly finer, fill the basket level (never tamp) |
| Nothing rises, valve hisses | Too much resistance | Grind coarser; check the filter plate holes for coffee cement |
| Coffee leaks at the waist seam | Gasket worn or grounds on the rim | Wipe the rim; replace the gasket ring yearly-ish |
| Weak, watery brew | Underdosed basket or overfilled water | Basket level-full; water to just below the valve |
| Metallic taste, gray brew | Soap-stripped seasoning or oxidized aluminum | Hot-water rinses only; brew a sacrificial break-in pot |
The gasket, the only part that wears
The rubber ring between the chambers does all the sealing, and it hardens with every heat cycle. The tells: coffee weeping at the seam, steam escaping sideways, or a pot that suddenly needs the grind changed after years of consistency. Replacement rings cost a few dollars, come sized by cup count (2, 3, 6, 9, 12), and take one minute to swap along with the filter plate they hold. A pot with a fresh gasket and clean plate is functionally new, which is why fifty-year-old moka pots outlive their owners.
The safety valve is not decoration
If the valve ever vents, the pot is telling you the brew path is blocked: grind too fine, basket tamped, or the plate holes crusted shut. Kill the heat, cool it, and clear the blockage before the next brew. Never brew with the valve pointed at anyone and never submerge the top chamber's underside in a sink of grounds; the valve seat collects debris exactly there. The full brewing method with the reasons is in the moka pot guide, and the ratio math per pot size lives in the ratio guide.
Related reading
FAQ
Why is my moka pot not brewing? Too much resistance in the coffee bed: grind coarser, never tamp, and clear the filter plate holes. If the safety valve hisses, that is the confirmation.
How often should I replace a moka pot gasket? Roughly yearly for daily brewers, or at the first seam leak. It is the pot's only consumable.
Why does my moka pot explode grounds into the top? Too little resistance: grind slightly finer and fill the basket fully so the water cannot blast through a thin bed.
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