voidroid wrote:Are we being a little too precious about clumps from a Robur-E?

Yes. Clumping is far from a problem on the Robur or Robur E. People look at clumps and think, "Bad!" I think that's largely because we associate clumps with smaller grinders that we start out with, which also happen to produce inconsistent results, which is coupled with a finickiness about pouring evenly. Of course, the relationship between those things (clumping, pour unevenness, and taste inconsistency) is not necessarily a causal one, but our minds abstract that. On the Robur E, or my Nino, I get some clumps, but they are generally not tight aggregations (I suppose), as they break up easily enough when I lightly tap the portafilter on the counter. And then I tamp, and I pour a good looking shot. Fairly often the cone isn't perfect at the beginning--both grinders distribute a little heavier in the middle, and if you don't deal with that you'll get a shot that beads in a ring before filling the center, for example.

But the cup... clumping isn't a problem there.

It would seem the 'clumps' on the ROBUR-E are as a result of grounds being mildly compacted in the chute before being 'sliced' into cubes at the chute exit by the anti-static screen. I think in order to have a repeatable dose in this design, it needs the mild compaction in the chute behind the screen. As long as the burrs aren't duds, then I don't see any degradation in the cup as a result. Initially disconcerting to see coffee cubes landing in the PF though, but if you give them a prod you can easily see them disintegrate as they do when tamped.

Cheers, Chris

I classify clumps in two categories, dense and light. Light clumps are not a problem. It is more like static cling, the clumps are loose and will powder when you touch them. The dense clumps are the problem. Those come from slower grinding grinders that extrude the grounds out the chute. Those clumps are hard packed like a snowball. That throws the density of the puck off and you get channeling.

I received my Robur-E about two weeks ago. My unit has the new style burrs and so far I have run about 30lbs of coffee through it (I have another 20lbs to go - kindly donated by a local roaster ). So far I have had no problems at all with clumping but I am not yet 100% happy with the taste or the pulls in general. My recollection of the Compak K10 WBC was that it did not require nearly as much to break it in...

Br,
Teme

Teme wrote: So far I have had no problems at all with clumping but I am not yet 100% happy with the taste or the pulls in general.

Ahh... You should not have abandoned your poor K30. It cursed you!


J/K I hope you'll enjoy your Robur.

I'll do my best. I hope things get better once I get another 20lbs of coffee through the Robur.

Br,
Teme

I assume once you've finished each session of sacrificial grinding that you are purging around 30grams worth to (largely) clear the grind path before you use the grounds for espresso? I am sure you probably also know, because of the larger grind path, adjustments to grind also take around 30grams to appear at the pf.

Whats your grind time and coffee weight for a double?

Cheers and good luck, Chris

Hi Chris,

3.5 secs for a 18 gram double. And yes, I do purge the stale coffee before use.

Br,
Teme

Well that all sounds good. Whats the problem with the pours?