I've had my Mazzer Mini for about 12 years now. I bought it when it was the be-all, end-all grinder for the home. It's worked well, and I've upgraded it over the years with a short hopper, funnel, SS catch tray, new burrs, etc. But these days the poor old Mini doesn't get any respect around here. I've always wanted to upgrade to a Titan-class conical grinder but could never justify the size/expense with the Mini chugging along with no problems. I tried a Pharos, but never really got into the hand-grinding thing.

Now the pendulum seems to be swinging back to large flat-burr grinders with the Mythos, EK43 Barista, EG-1, etc. Could I breathe new life into the Mini and at least partially hop on the new wave with some bigger burrs? I saw a few threads here on HB showing that you could install Super Jolly 64mm flat burrs in a Mini that ordinarily takes 58mm burrs. Rather than spend $2K+ on one of these great new grinders, I figured I would try spending $200 to upgrade my Mini and see if that would satisfy my upgrade-itis (for a while anyway).

So, I ordered Super Jolly burrs, upper burr carrier and lower burr carrier. They arrived yesterday, and I installed them today. It was surprisingly easy -- the Super Jolly parts fit the Mazzer Mini perfectly; it took about 45 minutes to install. I now have a Mazzer Mini Jolly grinder!

I captured some before/after data to compute grinding speed and % extraction to see if I could measure any difference. It is definitely grinding almost twice as fast. I'll post more data later once I crunch the numbers, plus any qualitative differences that stand out.

Here are some photos of the operation. And yes, I do clean my grinder with Grindz every few months. Looks like I need to do it more often... This project, at the minimum, is showing me the importance of low grinds retention in any new grinder I might invest in. I probably cleared away 20g+ of old grounds while removing the old parts!

The new parts to be installed. Shiny!


Old burrs/burr carrier with hopper removed:


After removing adjusting ring - this is the old upper burr carrier


This is after pulling out old upper burr carrier, can see lower burr / burr carrier. It had been about 4 years since I last pulled the upper burr carrier while replacing the burrs.


Comparing Super Jolly and Mini upper burrs/burr carriers. Doesn't look like you can go larger than the Super Jolly burrs.


Grind chamber after removing the lower burrs/burr carrier. Had to take the funnel off to pry up the lower burr carrier (screwdriver in through the grounds exit chute) from the motor shaft. A disgusting mess! A bunch of old coffee grounds and Grindz powder caked on the bottom under the lower burr carrier..


All clean!


New lower burr/burr carrier installed


Everything back together!

And now for the key question: do the shots taste any better/smoother/clearer etc (once the burrs have been broken in) ?

Exactly! The new burrs are obviously not broken in yet, but I notice a thicker mouthfeel and less sour notes with the beans I'm using now. I (want to) believe this morning's cap was noticeably nicer. That's the challenge with upgrading burrs -- it's hard to do an A:B taste comparison with a single grinder.

I pulled 3 shots before the change, and 3 shots after the change taking measurements of each with timer, scale, refractometer and VST software. Grinder was dialed in before each session yielding shots 40-45 sec (including 8-sec pre-infusion) and 1:1.9 brew ratio. I saw an average of about 20.6% extraction on the mini burrs, and 21.2% on the Super Jolly burrs. Not enough datapoints to really conclude much, but perhaps the slightly higher extraction with the Super Jolly burrs is reducing sourness. I'm using a La Spaziale Vivaldi II, set at 94C, 8 sec pre-infusion, IMS shower screen and basket, with Red Bird Espresso beans.

Grind speed is noticeably faster with the Super Jolly burrs -- 1.6x faster on average. The Mini burrs had an average grind rate of 0.82 g/s, while the Super Jolly burrs had 1.26 g/s. For a typical 18-20g grinding session this saves about 7 sec (16 sec vs 23 sec). Every little bit counts on hectic mornings!

I've got some Chromatic Gamut beans vacuum sealed in the freezer that I'll try next week once I'm done with my Red Bird. In the past the lightly roasted Chromatic beans were very sour no matter how finely I ground or how much I increased the brew temp. It will be interesting to see if the Super Jolly burrs will make a difference.

Doesn't the Mazzer Mini Electric (with the single dose funnel) come equipped with the larger burrs as standard?

Yes, but according to Difference between Mazzer Mini E burrs and Super Jolly burrs? the cut of the burrs is slightly less aggressive for the Mini E. Search on "mazzer mini e burrs vs super jolly" for other related discussions.

After reading this thread I realized that I already had everything that I needed to do this transplant. I have a Mini that was in storage, as I am using a Pharos. I had bought a beater SJ that turned out to have a bad bearing, also in storage. I already had new SJ burrs lying around.

The transplant took about an hour tops. Seems to be running fine. I will see how it performs over the next couple of weeks.

It looks like retention would be much lower with this mod / upgrade