# Grinder not delivering full dose into portafilter



## fatboyslim (Sep 29, 2011)

Hi,

Just when I thought I was getting on with my grinder, I've noticed larger clumps and supposedly fully dosed baskets of different heights (coffee height in the basket).

I've regularly been taking the burr ring off to inspect and have noticed the white plastic base with the paddles on, which rotates to push the coffee down the chute, has got tightly packed grounds stuck to one side of the paddle.

I've tried to attach a photo which I took after dislodging the packed grounds with a paperclip. Is there some environmental factor which is causing the grounds to pack like this against the paddles?

Or any other factors? Perhaps I need to use some Grindz to clean out the plastic base?

Any help is appreciated.


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## funinacup (Aug 30, 2010)

Do you weigh your beans in? Have you checked the weight of the grounds as opposed to just guessing by sight?


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## fatboyslim (Sep 29, 2011)

Yes always weigh beans before putting in hopper. Dose is always controlled going into the grinder but it's clear that the full amount isn't dropping into the portafilter and some is remaining, as I stated, stuck to the paddles.


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## DonRJ (Apr 3, 2010)

I have the progenitor of your grinder which I use for holiday french press (Dualit 75002) which has the same problem, My way of clearing it is to use the vacuum cleaner down the throat, the likelihood of the problem seems to be down to humidity and certain beans plus the basic grinder design. Having said that I occasionally have to give the big Mazzer a clean out but the higher rpm as a flat blade grinder ( greater centrifugal force) and a more efficient sweeping action reduces the problem.


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## fatboyslim (Sep 29, 2011)

I probably should have said this problem only just started occurring.

The only thing that changed was I was using a much lighter roast coffee and finding I needed to grind much finer than usual. I concluded that this must be a density issue where the coffee doesn't have sufficient weight to effectively exit the grinder.

Short term fix is to dose based on grounds rather than beans I guess.

Any other way around this problem?


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## jimbow (Oct 13, 2011)

As one grinds increasingly finer, more clumps are fairly inevitable unless, you get into much more expensive grinders. Whilst many people view dosers as evil they do help break up these clumps before they enter the portafilter.

Grind retention is also a problem with many grinders although the Baratza models do seem much better than most. Unfortunately grind retention is not a constant for any given grinder so I would suggest weighing the dose before and after grinding. Ideally you would do this every time you grind but as a minimum whenever the grind is adjusted. The first weigh is really just to limit waste, through grinding too much coffee, and the second weigh is to ensure the dose is correct.


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## DonRJ (Apr 3, 2010)

Other than some cunning modification to the sweeper assembly which others have talked about elsewhere online but not done to the Virtuoso, the only solution would be to upgrade the grinder to the likes of a Mazzer, Compak or similar flat burr grinder. You will still get some grind retention in the delivery chute though, I made a little bent wire tool to clear the chute in the Royal which takes a couple of seconds to do.


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## fatboyslim (Sep 29, 2011)

This is still happening









I'm starting to think sweeper assembly modification may be necessary. This wasn't happening before since I was using coarser grinds but recently (since VST) certain beans have required very fine grinds.

The grinds are still bulking up against the sweeping arms. Its easy enough to clean after using but is this due to the fineness of the grind or humidity, temperature or just the bean itself?

Anyone have a link to sweeper mod info?

Also I can't really think what to google for this problem, any ideas?


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