Cleaning and Calibrating the Gaggia MDF

Tools Required:

  • Phillips Screwdriver #1
  • Phillips Screwdriver #2
  • Awl (to help remove the rubber stoppers)
  • Slip-Joint Pliers

The following instructions outline the process of disassembling, cleaning, recalibrating, and reassembling your Gaggia MDF grinder. Be sure to read each step thoroughly before proceeding.



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  1. Empty both the bean hopper and the ground coffee dispenser.
  2. Locate and remove the two round rubber stoppers at the bottom of the bean hopper. Under each one will be a Phillips head screw.
  3. Remove the two Phillips head screws covered by the stoppers.
  4. Lift the bean hopper out the machine.
  5. Locate and remove the two small Phillips head screws that fasten the faceplate to the housing at the top of the machine.
  6. The adjustment ring (numbered from 1 to 39) can be removed by unscrewing the two brass hex bolts. These bolts will be visible when you remove the bean hopper.
  7. Removing the adjustment ring exposes the large round brass top burr plate. A good way to remove the top burr plate is to slide the bean hopper back into place (without the screws) and rotate it counter-clockwise until the plate is out. This will provide access to the grinding chamber.
  8. Remove the spring-loaded plastic p egs seated directly beneath the upper burr plate—these pegs cause the “ratcheting” effect associated with turning the bean hopper to make an adjustment.
  9. Thoroughly clean the grinding chamber. This includes all of the threads, both on the top burr plate and the matching threads on the wall of the grinding chamber. Clean the burrs as well. A group brush does a good job cleaning the parts and threads in the grinding chamber. Be sure to clear the chute between the grinding chamber and the ground coffee dispenser. A vacuum really helps to get into the tight corners and avoids a lot of mess.



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  1. Replace the burr plate by turning it clockwise until snug. Again, using the bean hopper to help works well.
  2. Making sure that the machine is switched OFF; plug the grinder back in. Place the bean hopper (without screws) back into place.
  3. Find “absolute zero” by turning the hopper clockwise, then back it off slightly to separate the burr plates. Proper calibration of the MDF grinder depends on finding absolute zero. This is the point at which the burrs first touch together while spinning. It is also the point at which the MDF is grinding the coffee as finely as possible. (Similar in texture to powdered sugar)
  4. The sound of the burrs touching while spinning is unmistakable. It’s a high-pitched metallic “chirp” plainly audible over the sound of the MDF motor.
  5. Turn the machine on for only 1-2 seconds. If the “chirp” of the burr plates is not heard, rotate the bean hopper either clockwise or counter-clockwise until absolute zero is located by the telltale “chirp.”
  6. Sometimes a false “chirp” can be heard. Another way to ensure that the burrs are at absolute zero is to listen for the sound after you switch the grinder off. It the motor sounds like it is winding down, then the burrs are still freely spinning. If the motor stops immediately, then the burrs are touching.
  7. Turn off and unplug the machine.


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  1. Remove the bean hopper.
  2. Replace the adjustment ring. The #1 or absolute zero setting should be facing front. Screw the two brass hex bolts back into place to secure the adjustment ring.
  3. Reattach the faceplate to the machine. Tighten the two small Phillips head screws back into place. The #1 on the adjustment ring should be centered in the window of the faceplate. It is alright if the adjustment collar is slightly off, the grinder will still be re-calibrated properly.
  4. Replace the bean hopper, the two bean hopper screws, and the two rubber stoppers.
  5. Plug the grinder back in and test to verify that it is working properly.