Coarse grind on Jura Capresso Impressa S9


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Dec 3, 2014
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I have a new-to-me Jura Impressa S9 fully-automatic coffee center. I became interested in Jura's fully automatics after being impressed by the quality of the drinks from my office's Impressa F7. I of course cannot afford a $2000+ coffee center, but I do like to tinker with mechanical things on occasion, so when I had the opportunity to acquire a high-end machine with a brew-group malfuntion, I went for it. The DIY brew group refurb was very easy and kinda fun, I also had to clear a sediment blockage in one of the water lines, which was easy to do with a small clean drillbit and the help of the machine to flush the line before refitting it. Now the machine runs beautifully through a brew cycle.

My only remaining reservation with this machine is with the grinder. The grind is very coarse, even on the finest setting. In my office's F7, the machine discharges a solid compacted puck of reasonably fine grounds, on my S9, the puck falls apart when ejected from the brew group, I assume because the grind is too coarse to stick together. Many of the reviews of the S9 complain that the grind is too coarse, so I'm not sure if this is just how the machine is, or if there is something wrong with mine. I can tell based on the sediment buildup and the brew group issues that the previous owner was not maintenance savvy, I fear that perhaps they did not know that the grind cannot be adjusted without the grinder running, and caused damage by adjusting the grinder with solid beans between the burrs. The machine has less than 700 total brews, which I wouldn't think would be enough for there to be any major wear on the grinder, the burrs don't look dull, and the grinder does not have any buildup in or around it. My office's F7 has ~1300 brews.

So my questions are,
Would you expect to see a difference between the performance of the grinder between two similar Jura brewcenters? (i.e. My S9 vs my office's F7)?

Do you have any suggestions for improving the grinding performance of the Jura Capresso Impressa S9?

Is there any way to repair damage possibly done by adjusting the grinder while it was not running?

Is there a way to adjust the grinder to a finer position than its factory limit?

Thank you in advance for your thoughts, advice, and expertise, I'm looking forward to hearing from you.
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I had a chance to dive back into the machine last night. I found that while the inner and outer conical burrs seemed to be in fair shape and worth cleaning to re-use, there were some easy-to-fix problems; The biggest problem was that one of the plastic tabs that holds the outer burr down on top of the inner burr had become disengaged, causing one side of the grinder to have far too much clearance, allowing for coarse grounds to fall through. This seems as though it could have been caused either by a poor re-assembly job by a previous would-be repair person, or by forcing the adjustment knob from coarse to fine with coffee beans lodged between the burrs, causing one side of the grinder to lift and separate. Either way, it was pleasantly easy to fix, and I probably didn't need to dive any deeper, but I gave the whole assembly a thorough disassembly and part-by-part cleaning anyway.

I also noticed that the grinder has likely been disassembled by a novice (not unlike myself) in the past, because a raised tab on the toothed adjustment ring was not aligned properly with the plastic stops on the bottom of the bean hopper, which allowed the adjustment knob to turn the toothed ring too far to the coarse side, and if turned far enough, disengage the teeth and spin freely. Yet another item that was very easy to fix, once I got myself oriented to the problem.

I am now thoroughly satisfied with the grinder performance of the machine.

Thank you to everyone who read this post, if anyone here is having similar problems and needs elaboration or clarification, please let me know, I would be happy to help.
Sadly the only way to make your grinders grind finer espresso is to actually modify the locking tabs that keep you from tightening it down further. Doing so will make it so you will not be able to send the machine back to Capresso should something fail and it requires to be sent it. Lastly if you do make the modifications make sure all the security pins on the tubing are all secured as tightening the grind down will put more stress on the tubing as the pressure rises in the group. Have fun modifying and don't forget to take before and after pictures to help guide your process as well as giving us a look of what you have done for future use by other forum members!
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Thanks for the reply ccafe. I am satisfied with the grinder now that I have it very clean and back to near-factory performance. Perhaps when I am completely finished with my DIY refurb I will get into some experimental modifications. :coffee:
How did you fix the grinder fineness knob? I clean my S9 and the knob just spins now and is not grinding it fine enough. Not sure what I did. Thanks.