Checked out your movie. Taking coffee porn to the next level. Nice.

Thanks Ken,

All tips and info greatly appreciated.

The Diadema Jnr uses a vibratory pump.

To my untrained eye the filter basket seems perfectly sound.

You might be onto something re inadvertantly finishing tamps on one side. I'll keep it in mind.

I'm trying to get the stockfleth distribution method happening. From all reports if done correctly it should work well.

I always dose till almost full then tap fairly firmly on a tamping mat I made. It is a stainless plate on a rubber mat. I then dose till the coffee is heaped and try the stockfleth move.

The bottomless PF is in the mail.

I do have a similar problem...

While everything is fine when using my doserless Innova, I do have a slanted extraction from my Cimbali Jr. Always on the south half (close to the handle). The south half gets extracted and blondes quickly, the north half squeezes a few black drops through.
The south side is the side where the water comes from the brewhead into the dosing chamber. To eliminate the doser I also used a little bowl to collect the coffee bevore I put it ino the basket.
So far I had no luck in getting anywhere close to the even extraction that I get from the Innova. The burrs are just a year old and the grinder is only used as my secondary...

cheers
afx

How are you handling distribution?

How are you handling distribution?

Either by finger or by a knock or two on the counter (vertically). Not much of a difference.

cheers
afx

I would suggest you experiment with a more rigorous distribution method. It should solve the described problem. Either the Schomer method or the Stockfleths one should work.

Dose (using the doser) from the Cimbali until you have a good heaping pile.
(Optional depending on desired dose: Give it one to three quick raps vertically against the grinder fork.)
Top off the dose to create a heaping pile.
Distribute using one of the methods above.
Tamp.
Go...

afx wrote:Always on the south half (close to the handle). The south half gets extracted and blondes quickly, the north half squeezes a few black drops through.

I've noticed the same thing with Junior and attributed it to (a) uneven distribution due to factors like dosing w/o rotating the portafilter, or (b) filling high enough to grate the puck on the south side during lock in, but not high enough to get the "Paul Bassett" updosing effect (which renders the grating irrelevant since the whole puck surface is intentionally grated pretty hard). Chris also mentioned in another post baristas that favor one side when tamping will see south-side channeling.

A remote chance is that the brew pressure is too high. I intentionally raised it to produce some of the more disasterous effects for Perfecting the Naked Extraction, like this one I called "System Meltdown":



The pressure was set to 11 bar.

I'll toss some weirdness that can occur. On my used Super Jolly it is missing a deflector screen in the doser. What happens is the finer grains fall close to the edge and the coarser grains fall near the middle. When dosing, tamping and pulling the shot it will act like a canted tamp. Nothing will get extracted in the 6 o'clock half of the portafilter and the other half gets overextracted.

Of course nothing a well placed and bent business card couldn't fix!

I think I've solved my channeling problems, for now anyway. After trying many of the suggested fixes the thing that helped was changing my tap in between tamps. I tamp, tap, tamp then lightly polish. The tap was light and directly opposite where I was getting the channeling. I tried tapping even more lightly and with a more glancing blow, but this time I tapped one of the lugs. So far so good.
Is there a known problem with tapping the lugs? Do they become misshapen over time?
The best thing is, in trying to fix the channeling I've gotten some great tips and more than likely improved my distribution and levelling.