This is for all those Hario Mini Mill lovers who are curious how to make their hand grinder significantly more consistent by using a simple modification. If you’re not an owner of this fantastic hand grinder, check out its review!
? 2020 UPDATE: The new Hario Mini Slim resolves a lot of the issues that this mod guide used to resolve. While this mod will still work for older grinder models, I largely just recommend upgrading to the new, far-better version 🙂
Back to the mod guide!
It’s no secret that the Mini Mill doesn’t exactly compete with a commercial grinder, but this little guy is definitely good enough for most people. There is one problem however: coarse grinds tend to be fairly inconsistent with many different sized grounds.
This problem is a result of two pieces, the metal rod and the outer burr, not being set in their places firmly enough. This enables some wiggling, which ends in unevenly ground coffee. The solution is so simple you will doubt it: scotch tape. Yes, those clear strips are the key to the Hario Mini Mill mod.
Before we apply tape, disassemble your hand grinder and clean it well. Don’t use water on any of the ceramic pieces, it could shorten the grinder’s life. I just use a paper towel and little brush to get small particles off.
The Metal Rod
This part is fairly simple. Right above the screw portion of the rod are two small protrusions on either side. Just above this is where the tape is going around the rod. Put just enough on so that the rod can fit through the black hopper and spring, but be set firmly. I used about four layers of tape, but experiment yourself to find the best fit.
Once you’ve done that, place it back through the tunnel and attach the pieces that hold it in place. You should be able to notice much less wiggling.
The Outer Burr
This part is a little more difficult. Split a piece of tape into two long strips using scissors. Make sure not to cover the indentions where the burr and body meet. Take your time and try not to allow lots of tape going over the edges. Here I used three layers.
After you’ve applied this mod, settle it back into the bottom of the body and confirm that the wiggling has decreased immensely. If not, apply another layer of tape. As before, experiment!
And that’s the Hario Mini Mill mod! After reassembling you’ll notice that the coffee grounds are much more consistent, especially when you’re grinding coarsely. Good luck, and happy brewing!
Do you have any questions or suggestions about how to make this guide more clear and reader-friendly? Drop a comment below!
September 8, 2014 Addition
I’ve discovered a couple extra things that help with grind uniformity when using the Mini Mill.
1. Solid Surface – It seems that using both arms to swing the grinder around to achieve a very quick grind is not ideal for consistency. Placing the grinder on a solid surface like a counter or table while grinding seems to be makes a noticeable difference, although it requires more effort. For speed, swing like a madman. For consistency, let gravity pull the beans down naturally.
2. Maintenance – Take care of your grinder, and it will take care of you. This includes unwrapping the scotch tape and reapplying more after a quick cleaning. Resist the temptation to use water on the ceramic parts and invest in a toothbrush you can use on your coffee equipment to knock off fine particles.
As always, if you know of any other tricks or ways of improving the daily grind, post in the comments!
November 3, 2014 Addition
Aha! I finally did a grind comparison and published the results. Skeptical of this mod using extremely simple materials? Check out the Hario Mini Mill Mod Grind Comparison!