Do not do this in a burr grinder you use for coffee.
The flavour problem
Spice oils are far more persistent than coffee oils and they penetrate the grinder’s surfaces. Cumin, cardamom and cloves in particular will flavour coffee for weeks afterwards.
No amount of cleaning tablets fully removes them. People who have tried this report tasting it months later.
The damage problem
Hard spices chip burrs. Cinnamon bark, whole nutmeg, dried ginger and star anise are harder and more fibrous than coffee beans.
Sticky spices clog. Vanilla, cardamom pods and anything oily pastes up the chamber.
Sugar is worse still — it caramelises with friction heat and cements the burrs.
The exception that is not one
Blade grinders are a different case: a cheap blade grinder is a perfectly good spice grinder, and many people keep one for exactly that.
Just do not use it for both.
What to use instead
A dedicated blade grinder for spices — inexpensive, and effective for the job.
A mortar and pestle, which is better for most spices anyway.
A mill designed for pepper or salt.
If you already did
Run cleaning tablets, disassemble fully, brush everything, and expect to taste it for a while.
If it is a cheap grinder, consider it converted to a spice grinder and buy a new one for coffee.
Last reviewed 8 August 2026