Empty bean hopper before changing grind settings?

Grinders are one of the keys to exceptional espresso. Discuss them here.

#1: Post by fizguy »

Do I need to empty all coffee beans from my burr grinder (Rocky) before setting to a finer grind? The literature does not mention this. Thanks!

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#2: Post by jamhat »

No, you don't need to empty to hopper, but you do need to run the grinder as you tighten the setting. It can be a real pain with the doserless model.


#3: Post by Endo »

In case it's not obvious, no need to run if you are going more coarse.
"Disclaimer: All troll-like comments are my way of discussing"

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#4: Post by HB »

Reposted from MACAP M4 overheats/shuts off running empty:
HB wrote:Some vendor/manufacturer advise that you always run the grinder during an adjustment. Their concern is binding the motor by forcing the burrs together when the grinding chamber is full. Rather than explain the reasons behind their recommendations, they offer blanket statements, with the caveat that they'll void your warranty if you don't do as prescribed. I appreciate their predicament with a public that unknowingly does damage to new equipment and blames the reseller. However, to be clear:
  • Grinder motors generate a lot of heat; they'll all overheat eventually, even if run empty
  • Running the motor to the point that the thermal protector cuts off power is a bad thing
  • How long it will take to overheat depends on the grinder. The owners manual may state the max on/min off time, it may not. I advise no more than 30 seconds on and a minimum of one minute off
  • There is no risk of binding the burrs if the adjustment is coarser
  • There is no risk of binding the burrs if the grind chamber is truly empty.
To answer your question more directly, you should empty the hopper and the grinding chamber if turning finer, unless of course you're willing to waste a bit of coffee by running it while adjusting. It is not necessary to empty the hopper and grinding chamber or run the motor if turning coarser. Very small adjustments either way can be done without emptying the hopper or grinding chamber, but there is a slight risk of the burrs binding and stalling the motor. Powering the motor without it spinning is a bad thing.
Dan Kehn


#5: Post by Endo »

On slightly different but related topic; Do you think there is any danger restarting the motor after it has turned off but is still spinning (winding down)?
"Disclaimer: All troll-like comments are my way of discussing"

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#6: Post by sweaner replying to Endo »

I don't see why that would be a problem.
LMWDP #248

fizguy (original poster)

#7: Post by fizguy (original poster) »

Let me describe my recent experience:

I bought a press pot and wanted to try it out, so I adjusted my Rocky from 12 to about 30. Later I went to adjust back to 12 and was met with some resistance so I stopped. I did not push it because I did not want to damage anything. Because of some other things happening in my family I had to leave it at that.

The next day my wife dumped the beans but still could not adjust to a finer grind. Later that day I tried grinding at 40 and the machine was not working. I don't believe the burrs were turning at all, and there was certainly no grinding occurring. With a sinking heart I disassembled the upper and lower burrs and cleaned them out with a brush, then put it all back together. In the process I noted that the lower burrs would sometimes turn smoothly, and were sometimes tight. I am sure it was not cross threaded. I turned until the burrs touched, then backed off a little bit and put the upper burrs back on. I then proceeded to grind and all seemed well. Finally, I adjusted to a lower grind setting and noticed that I felt the same smooth/rough pattern as I adjusted. This time I was more aggressive and got the setting to where I wanted it.

Hopefully you could follow my story. My question is, does it sound like something is wrong? Secondly, I am pretty sure the grind I got from a setting of "12" before will now be completely different since I moved things around. Does that sound about right?

Thanks again for your help. I am hoping to be able to use this grinder for both espresso and press without too much trouble.


#8: Post by Beezer »

Was the grinder running when you tried to adjust it to a finer setting? If not, you might have jammed the burrs with some leftover coffee. Taking it apart and cleaning it out should take care of the problem, unless you managed to seize the motor by trying to run the grinder when the burrs were jammed. Sounds like you didn't do any permanent damage though if you're able to get the grinder to work now.

The tightness while adjusting may also be from coffee grounds getting into the burr carrier threads. You need to get them as clean as possible when you disassmble the grinder, otherwise there can be resistance when they're put back together.
Lock and load!

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#9: Post by cafeIKE »

fizguy wrote:I am hoping to be able to use this grinder for both espresso and press without too much trouble.
Not a good idea. Press pot requires a different grind distribution than espresso. When you go from coarse to espresso there will be leftover coarse coffee in the grinder that will end up in your shot. Save up and get a dedicated press grinder. It will make your press coffee better and espresso making less frustrating.

fizguy (original poster)

#10: Post by fizguy (original poster) replying to cafeIKE »

My goodness this is an expensive hobby!