Why Is My Grinder Not Grinding or Feeding Coffee?

When your grinder stops producing coffee or dramatically slows down, there are a handful of likely causes — and most of them you can resolve yourself without a service call.

Grinder feeding issues are more common than most users expect, and they're rarely signs of serious mechanical failure. Work through the most common causes in order before assuming something is broken.

Coffee Stuck in the Chute

The most frequent cause of a grinder that sounds like it's running but produces no coffee is a blockage in the exit chute. Coffee grounds — especially from oily or dark roasts — can compact and clog the chute between the burrs and the outlet. Turn the grinder off, use the provided cleaning brush or a small stiff brush to clear the chute from below, and try again. This is especially common after switching to a finer grind setting or a darker, oilier bean.

Foreign Object in the Burrs

If the motor runs but the burrs won't spin — or you hear a hard grinding or clicking sound that wasn't there before — a foreign object may be lodged between the burrs. Stones, small pebbles, and even fragments of dried fruit occasionally make it into coffee bags, particularly with naturals and wet-hulled coffees from certain origins. A single small stone can jam the mechanism completely.

Turn the grinder off and unplug it. Remove the hopper, then remove the top burr (procedure varies by grinder — check your manual). Inspect the burr chamber carefully and remove any debris before reassembling. Never force the burrs to spin if they're meeting resistance — this can damage the burrs or motor shaft.

Burrs Clogged with Coffee Oils

Over time, coffee oils build up on and between the burrs, restricting flow and reducing grind quality. A grinder that's slowing down, producing clumpy grounds, or smelling stale is often past due for a cleaning. Run Grindz cleaning tablets through the grinder per the package directions. For a deeper clean, remove the top burr and brush both burrs with a stiff brush before reassembling. Dark, oily roasts accelerate this buildup significantly — if you grind them regularly, clean more often.

Overfilling the Hopper or Static Buildup

Some grinders — especially single-dose grinders with smaller hoppers — feed inconsistently when the hopper is too full. The weight of beans above the burrs can cause them to compact at the inlet. Try dosing only what you need for one or two brews at a time rather than filling the hopper completely.

A related issue is static electricity. In low-humidity environments or when grinding light roasts, beans can cling to the hopper walls via static charge and simply stop falling. You'll hear the motor running while nothing feeds through. A simple fix is the RDT (Ross Droplet Technique) — add a single drop of water to your beans before grinding. The moisture dissipates static without affecting the grind. Tapping the side of the hopper can also dislodge beans temporarily, but RDT addresses the root cause.

Grind Too Fine or Wrong Bean Type

Very fine grind settings combined with oily or humid beans can cause the burrs to clog or bind. If you've recently adjusted significantly finer or switched to a darker, oilier roast, try stepping slightly coarser and see if flow resumes. This is especially relevant for espresso grinders operating at their finest settings.

Bean moisture matters too. Beans that have absorbed ambient humidity — from being stored in an open bag or near a steam source — grind poorly and tend to clump into a paste-like consistency that coats the burrs quickly. Fresh beans stored in an airtight container will feed and grind noticeably better. If you use pre-ground coffee in a grinder hopper (a common mistake), it will almost always clump and jam.

When the Problem Is Mechanical

If the grinder motor sounds strained, makes grinding or clicking noises it didn't before, or won't turn on at all, the issue may be mechanical. A few things to check first:

Safety interlock. Many grinders won't operate unless the hopper is fully seated and locked. If the hopper is slightly misaligned or the locking tab isn't engaged, the grinder simply won't start — this is by design. Remove and reseat the hopper, making sure it clicks into place.

Motor thermal cutoff. If the grinder stops mid-session after heavy use, it may have tripped its built-in thermal protection. Some motors automatically cut out when they overheat — particularly on smaller home grinders used to grind large batches back-to-back. Unplug the grinder and let it cool for 10 to 15 minutes before trying again. If it runs normally after cooling, reduce how much you grind in a single session.

Worn or seized motor. If the grinder hums but nothing moves, the motor shaft may be seized. This typically requires service. Contact the manufacturer or reach out to our support team for next steps.