The SSP HU burrs are a favorite for espresso on the Z1. They also produce a lot of fines, and while they are new, those fines can pack into the grind path. This is normal, and it fades as the burrs season.
What it looks like
Grounds stop coming out of the chute, or a grind finishes short.
Grounds pop back up into the funnel instead of falling into the dosing cup.
A thick coffee paste builds up around the burrs when you open the grinder.
The dial feels stiff or chirps when you move back toward finer settings.
Why it happens
HU burrs have large finishing flats, and the Z1 holds them in near perfect parallel alignment. That combination grinds beautifully but leaves fines with less room to escape. Occasionally fines pack into the grind path and push the next grind back up toward the hopper.
New burrs make this more noticeable. Coated burrs like the HU usually settle within 1 to 2kg of coffee, and the clogging eases as they wear in.
Keep grounds moving
- Tap the open funnel. After the grind, while the grinder is still running, give the top of the open funnel a few palm taps. Make sure the funnel cap is off. This knocks loose fines in the chute before they build up.
- Adjust finer with the grinder running. Moving from coarse toward espresso, you may feel some resistance. With the motor on and your zero point set correctly, you can push through it.
- Grind in the usual HU range. Most HU users land between about 150 and 270µm for espresso, depending on machine, basket, dose, and coffee. Larger doses need a coarser setting. The coarser you go, the more easily grounds flow out of the chute.
- Go easy on RDT. Start with 1 to 2 light sprays. Too much moisture helps fines stick and form paste.
- Grind dark, oily roasts slightly coarser. Oily beans clump more easily, and the HU has a narrower tuning window with them.
Season the burrs faster
To get through the break-in period quickly, grind 500g at a time at about 500µm, resting the grinder 5 to 10 minutes between sessions. Recheck your zero point once the burrs settle.
If it clogs
- Unplug the grinder and open it. See Opening, Cleaning, and Closing Your Z1.
- Brush out the burrs, grind chamber, and chute completely.
- Reassemble and reset your zero point on a true chirp. HU burrs are prone to false chirp, so watch the video below before you rezero.
- Grind a coarse dose first, then move back to your espresso setting.
Still clogging?
If these steps do not work, please contact support at info@zerno.co.
Related
Troubleshooting: False Chirp and Zero Point Shift on the Z1 | Setting the Zero Point on Your Z1 | Z1 Grind Settings, RDT, and Retention | Opening, Cleaning, and Closing Your Z1