# K30 cannot grind fine enough



## pantherish (Aug 26, 2015)

Ok so I know there have been a few posts on this topic before and I believe I have read them all and tried everything suggested as well as advice from other online sources. I still can't get my K30 to grind fine enough to get a good pour from a light coffee. I am trying to achieve this recipe: 18g in, 36g out in 30-40s (this ignores the pre-infusion setting on my machine, I have also tried using another espresso machine without pre-infusion). My espresso machine (previously Nuova Simonelli Oscar v1 - portafilter pressure 7.5bar) and currently Lelit Bianca (boiler pressure set to 8bar and am able to see/adjust pressure in the portafilter due to the gauge). I am using lighter roasted coffees, typically Foundry espresso blends... I have heard from some that the K30s can struggle with grinding fine enough for lighter roasted beans, but have also heard elsewhere that the K30 is the grinder of choice for hipster cafes serving light roasted coffee... This is really my last attempt at solving this problem before I look to sell the grinder and replace with something else.

About the grinder:



2015 model with brass ring that holds the top burr - apparently this was a big improvement on previous models


Light commercial use before I bought the machine


Very light home use (1-3 coffees per day) since I bought the machine


New (proper Mahlkonig) burrs fitted <1 year ago


Previously worked perfectly (was grinding around the 5 mark to get good pours before), slowly but steadily I ended up having to grind finer to get good pours, eventually I realised I was at the limit


Standard (2-3kg?) Mahlkonig hopper


 Steps I've taken (on advice of knowledgeable friends/members of this forum and on advice of UK Mahlkonig distributor DMAUK/La Spaziale😞



Replaced burrs (and double checked they are fitted correctly - top burr fixed, bottom burr rotary)


Replaced silicone flapper


Adjusted motor to ensure it's sitting level


Thoroughly cleaned and assembled/re-assembled the machine (around 10 times now)


Lubricated the top burr holder


Added weight above the beans in the hopper (4 bags of 100 marbles)


I am confident that I am zeroing the burrs correctly - setting the "chirp point" having thoroughly cleaned the burrs and grind chamber, very carefully adjusting to get the grind at zero (or even sometimes at 1 for the purposes of testing/experimenting)


So far, no joy, the grinder is set to virtually at the chirp point and I'm lucky to get 35g out in 25s.

Many thanks!


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## Inspector (Feb 23, 2017)

Have you tried to updose? Because when you grind too fine coffee grounds dont fill the basket enough.


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## pantherish (Aug 26, 2015)

Haven't tried that, I'm using a 17g VST basket so already kind of upping the dose, there is room for more... I have been told that this grinder should be capable of choking my machine though. So that tells me something isn't right?


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## Mrboots2u (May 10, 2013)

pantherish said:


> Haven't tried that, I'm using a 17g VST basket so already kind of upping the dose, there is room for more... I have been told that this grinder should be capable of choking my machine though. So that tells me something isn't right?


 Are you single dosing ? Is this across a number of different coffees.

What method did you use to zero burrs


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## pantherish (Aug 26, 2015)

I'm not single dosing the coffee, typically empty 1-2kg of coffee into the hopper and recently have added the marbles on top of the coffee for extra weight.

I'm zeroing pretty much as shown in this video. Get the burrs roughly zero'd then do fine adjustments using the 2 hex bolts which attach the top plate to the burr carrier.

Yes this is across about 10 different coffees now.


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