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Thread: Grind retention

  1. #1
    Senior Member sidewayss's Avatar
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    Grind retention

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hoping to get some advice on minimising grind retention that seems to build up in chutes.
    My Mazzer Robur doserless retention is at it,s worst when I replaced the old burrs with new ones.
    Took a substantial amount of time dialling it in, and then discovering termite sized mounds were building up inside the dispenser chute.
    Every fourth dose a quick whack on the side was a necessity to release, creating a mess below.
    Advice anyone?
    Thanks in advance:thumbup:

  2. #2
    TC
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    Hi Gary,

    Some Mazzer users have had success by removing the top left hand corner of the anti-static mesh in the throat...

    FWIW, I don't bother. My first grind is for the knock tube

    Chris

  3. #3
    Mal Dimal's Avatar
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    Quote Originally Posted by Talk_Coffee View Post
    Hi Gary,

    Some Mazzer users have had success by removing the top left hand corner of the anti-static mesh in the throat...

    FWIW, I don't bother. My first grind is for the knock tube

    Chris
    Ditto...

    At the end of every session though, I do brush the internals out with an artist's paintbrush via the discharge chute (having completely removed the antistatic mesh for this purpose). First 4-5g of a new session goes in the bin and then the real coffee making fun begins...

    Mal.

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    Sound like the new burrs may need seasoning

  5. #5
    Senior Member sidewayss's Avatar
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    Thanks for the advice Chris and Mal.

    The antistatic mesh was removed a while back to improve the dosage consistency.

    Would it be correct to say that the new burrs produces certain fines that tend to congregate on the slope of the funnel and create the build up effect?

    Seems worse in the mornings when it's cooler and higher humidity. During the middle part of the day and afternoons it's not so bad.

    Gustopher, I would agree it will take some time before the problem eases when the burrs are "run-in".

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    The way conical burrs work, when they grind the coffee they will create micro-particles and larger macro-particles. When they hit the chamber directly below the blades, the three windmill like paddles will evenly disperse them down the chute. The anti-static mesh is actually there to ensure the ground coffee flows down the funnel and into your basket with a consistent mix of macro and micro particles. If you take the mesh off, the static build up will immediately make the micro particles cling to the side of the funnel. This is bad a) for consistency in the dose, and b) without those micro particles in your dose, the shot will come out thin looking, and lacking in body and flavour that the micro particles add. You should find an immediate effect if the mesh is attached again.

    As far as minimising the build up, I would look at regularly cleaning out the grinder chamber itself. Which isn't all that daunting ... Make sure you mark where the grind is set too, and also how low the grinding regulation ring is. When I pull it apart (once a week) I use a vacuum cleaner to get rid of all the grinds (vacuum cleaners are an under utilised resource in a coffee shop! Just make sure the four springs are safely put aside ...) using a brush to loosen up the grinds stuck in the threads, and a harder brush to get rid of any caked up gunk. When replacing the regulation ring, just make ultra sure no grinds have been left inside the threads. After a while of cleaning you may find it needs a little grease to help it move easily when changing the grind during service. If you get the vacuum cleaner, at the end of each shift vacuum out the chute.

    The first time this is done you will be very surprised at how much has built up, but regularly cleaned, and teamed up with the anti static mesh, you'll find far more consistent doses, and less build up in the chute.

  7. #7
    Mal Dimal's Avatar
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    Quote Originally Posted by Nzmcam View Post
    This is bad a) for consistency in the dose, and b) without those micro particles in your dose, the shot will come out thin looking, and lacking in body and flavour that the micro particles add.
    Have never observed this where we live...

    Removed the so-called anti-static grid not that long after planting the Kony-E in pride of place next to the DJE Dual Boiler. Never have a static problem and when the grinds are shooting out of the discharge chute into the funnel, they basically just hit the front wall of the funnel and take a nose dive out of the bottom.

    The only time I notice any fines adhering to the internal surface of the funnel, is when I am brushing out the chute and chamber area after a coffee session. I understand what you're saying and why static may be more of an issue in some locales/situations than others and the reasoning behind Mazzer finding the need to use such a device. It's not needed in all cases though...

    Mal.

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    Quote Originally Posted by Dimal View Post
    It's not needed in all cases though...
    My understanding is that static is less of an issue when atmospheric humidity is higher.

  9. #9
    Mal Dimal's Avatar
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    Yep...

    That's true. We rarely get below 50% R.H. where we are, so static issues are equally rare... And I'm happy because I get to clean out the discharge chute and grind chamber after every coffee session. Love a clean grinder...

    Mal.

  10. #10
    Senior Member sidewayss's Avatar
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    Here,s an update so far.
    Since the burrs have been run in, the retention issue has been minimised, so that means the amount of retention is now at the level prior to the burr replacement.
    Currently, heavy usage seems to cause a little grind retention which is usually swept away with the paint brush.
    The problem only occurs with the blend and hardly on the other Robur containing single origins.



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