If you’re like me, you’re always looking for a better cup of coffee… whether that’s using fresher coffee beans, trying a new method of brewing coffee or buying a new grinder. If you’ve purchased a new grinder, you may have noticed that it ground up the coffee really well at first and the resulting cup tasted amazing… but after months or years passed, the coffee didn’t seem to come out the same and the brew didn’t taste as fresh as it once did.
This is normal and is a byproduct of grinding coffee beans, as residual oils from coffee beans (especially dark roasts which typically cause the greatest amount of oil on the coffee beans) get trapped inside the grinder along with coffee grounds from prior grinds.
Ground coffee goes stale within 30 minutes of grinding and coffee oils go stale (rancid, really) very quickly. Anything left in your grinder will degrade the next batch of coffee you put through the grinder as old, rancid oils and stale ground coffee mix with newly ground coffee which ultimately get put back into the cup you brew. This cycle repeats itself and snowballs until the grinder is either cleaned properly or breaks down due to the stale ground coffee and coffee oils causing problems, such as slowing the machine down, meanwhile the cup you brew gets continually worst.
How should you clean your coffee grinder?
A really great way to clean out your grinder is to use uncooked, white rice. If you use a blade grinder (and we highly recommend upgrading to a burr grinder!), fill it with white rice up to the blades. If you use a burr grinder, put about 2-3 teaspoons worth of white rice and set the burr grinder to a fine grind (espresso) setting and start grinding.
After you’ve finished grinding, you’ll notice immediately that large clumps of previously ground coffee are now clinging to the powdered, ground white rice and after dumping the grounds out, you should see spots you could never clean before coffee-ground free. The inside of the grinder should also be a lot cleaner than before as most of the old, rancid coffee oils also attached themselves to the white rice (they’re attracted to the starch in the rice – that’s why this technique works so well).
Repeat this process until the ground rice no longer has any black particles in it. The first run will get most of the bigger coffee particles out. Subsequent runs will further clean the grinder. After the rice you run through the grinder no longer picks up any coffee residue and is just as white coming out as it was going in, run a small batch of coffee through the grinder… but use some cheap or not-so-fresh coffee you don’t mind getting rid of. The point here is to get rid of any remaining rice particles left in the grinder with this final run of low quality coffee so new batches come out tasting great.