The Barista Express's built-in pressure gauge should climb into the shaded "extraction" zone during a shot. If it stays low, work through these in order.
01Grind too coarse
By far the most common cause. Turn the grind dial finer in single-number increments and pull a test shot after each change — the built-in grinder makes this fast to test compared to machines with a separate grinder.
02Dose too low or uneven tamp
Use the Razor dose-trimming tool included with the machine to level your grounds precisely before tamping — an uneven puck is a common cause on this model specifically, since the built-in grinder can dose slightly unevenly into the portafilter.
03Worn group head gasket
If you see spray or hear hissing at the portafilter during extraction, the gasket has likely lost its seal. See our general group head gasket replacement guide — the process is the same across brands, just check Breville's part number for the correct 54mm size.
04Scale buildup restricting flow
If the CLEAN light hasn't been solid recently and it's been months since your last descale, mineral buildup could be restricting water flow enough to prevent proper pressure. See our descale mode guide if the machine won't start the cycle.
| Symptom | Most likely cause |
|---|---|
| Fast, watery shot | Grind too coarse or dose too low |
| Spray/hissing at portafilter | Worn gasket |
| Gradual weakening over months | Scale buildup |