How to Sharpen Coffee Grinder Blades

If you’re a coffee lover, chances are good that you have a coffee grinder at home. The only problem is that you may not be getting the most out of your machine because you haven’t sharpened your blades yet. Learning how to sharpen coffee grinder blades is pretty simple.

How to Sharpen Coffee Grinder Blades

Coffee grinders are a great way to make a fresh cup of coffee in the morning. However, it is essential to remember that these machines need maintenance to keep working correctly.

Coffee grinders have blades that can become dull over time and need sharpening or replacing. The blades on your grinder are essential in grinding beans and spices to the correct size.

A woman wearing black long sleeves and eyeglasses puts whole coffee beans on a black coffee grinder in a coffee shop

Method 1: Using Rice

What you will need:

Step 1: Put Your Grinder on Its Side on a Flat Surface With the Lid Open

Look at the blades inside and see if there is any coffee stuck to them. If there is, use a brush made for cleaning coffee machines to scrub off any residue that might be left over from previous grinds.

Step 2: Pour Uncooked Rice

Pour some uncooked white rice into the chamber of your grinder so that it fills about 1/3 of the chamber with rice. This is important because if there isn’t enough rice in there, the blade won’t be able to spin freely around its axis, so when you turn on your grinder, it will just sit there and not turn.

Step 3: Grind

Now turn on your grinder at its highest setting and watch as the blade spins inside its chamber! After a few seconds, unplug it from the power source and remove the lid.

Step 4: Clean

Once the grinder has cooled off, remove all the rice and shake out any excess powder inside the chamber. Now take a paper towel or cloth and wipe down any remaining rice dust left over before proceeding.

Step 5: Reassemble

Finally, put your lid back on, ensure everything is aligned so it closes properly, then plugs in your grinder and give it another spin!

Tip: Avoid washing the blades with soap or detergent because these products will damage and affect their flavor.

Method 2: Stone Grinding

Over time, your blades will begin to dull and lose their sharpness. This can cause several problems, including overheating, poor grinding consistency, and even damage to the motor. A stone grinder is a convenient way to sharpen your grinder blades before they get too dull.

Step 1: Turn off the Grinder and Unplug It

Use pliers to remove the top of the grinder (the lid), so you can access the burrs underneath.

Step 2: Use a File or Stone

Sharpen each blade’s side at approximately 15 degrees while holding it steady with your other hand. You may need to hold down the burr with pliers while you do this.

Once both sides have been sharpened, put the lid back on and test out your new grinds by putting some beans in there and turning them into powder!

Method 3: Hand Sanding

Hand sanding is done using sandpaper to smooth out any rough edges on the blade so that it can cut through the beans more easily. To sharpen your coffee grinder blades with sandpaper:

  1. Place a few coffee beans or ground coffee in a bowl and pour water over them, so they’re completely submerged. Let them soak for about 30 minutes.
  2. Remove the blades from your grinder and dry them off with a towel or paper towel. Then place them on a clean surface and use fine grit sandpaper to lightly sand both sides of each blade.
  3. Dip your fingers into the water/bean mixture and run them along both sides of each blade while you’re still holding onto the handle of your grinder (make sure that you don’t dip too deep). This will remove any dirt or debris clinging to them after they’ve been cleaned with sandpaper, ensuring they’re clean and ready for sharpening!

How Can I Tell My Blades Are Getting Dull?

Coffee blades can be dulled by repeated use. If you’re not sure if your coffee blades are getting dull, there are a few signs to look for.

A black and silver coffee grinder near a bundle of wooden stirrers and white saucers on a table near the brown wooden stairs

Inconsistent Grind Size

This can cause over-extraction of some grounds and under-extraction of others. An excellent way to test this is by pouring your ground coffee into a filter paper, folding it up, and steaming off the top of the grounds. If they don’t break into an even layer, your blade is dull and needs replacement.

Clumpy Grounds

Your grinds are clumpy or sticky together instead of being uniform in size. The consistency of the grounds will affect how much flavor they release during brewing, so if one part is under-extracted and another part over-extracted due to clumping, you won’t get an even cup of coffee with the great flavors intact!

The Edges of the Blade Feel Blunt

You can tell if your coffee blades are getting dull by how they feel. If you run your finger over the edge of a blade, you should feel very little resistance. If there is any friction at all, it means your blade is getting dull.

Tips to Keep Your Coffee Grinder Blades Sharp

Coffee grinders are all about precision. A dull blade means you’re not getting the most out of your beans and coffee grounds, so keeping them sharp is essential. If you’ve ever used a coffee grinder and wondered why it wasn’t as refined as it could be, then it’s likely that your blades are no longer sharp.

The good news is that there is an easy way to keep your grinder blades sharp, so you can get the most out of your beans every time.

1. Clean the Blade

One of the easiest ways to keep your blades sharp is by cleaning them regularly. This might seem like an extra step at first, though if done correctly, it will help sharpen your blades over time thanks to its ability to remove residue from previous grinds that could otherwise clog them up or dull them over time.

If cleaning isn’t part of your routine, you’re missing out on some delicious flavors in each cup of coffee!

2. Sharpen Regularly

The best way to keep your grinder running smoothly is by keeping the blades sharp. The more you use your grinder, the more frequently you want to sharpen the blades.

Ideally, you’d take care of this task before each use. However, this might not be possible if you’re someone who uses their grinder infrequently or doesn’t have a lot of spare time. In that case, it is recommended to sharpen every 6 months.

Related Questions

Can Coffee Grinder Burrs Be Sharpened?

Coffee grinder burrs can be sharpened. As with any tool, they will eventually lose their edge and need to be professionally sharpened or replaced. While most coffee grinders have removable burrs that allow you to easily remove them for cleaning or sharpening, some grinders have fixed burrs that are not removable.

How Often Should I Sharpen My Coffee Grinder Blades?

You should sharpen your grinder blades every six months to remain sharp and perform their functions. If you don’t sharpen them regularly, you may have difficulty operating your machine because of accumulated dust and dirt on the blades.


Sharpen your grinder blades using rice grains, a file, or a stone, or sand them using coarse material. If your blades are dull, the grind will be inconsistent,  come out clumpy, and the edge will feel blunt. Maintain the blades’ sharpness by cleaning and sharpening them regularly.