Nick wrote:Just read through this thread for the first time. It's fascinating to read about the various testing methodologies, especially the techniques used to overcome the "low volume problem" (i.e., fashioning alternative bean hoppers, weighing down with tampers, etc.).
I was also interested to see that the caked-on messiness that we experience in the grinding chamber on the Robur and Kony aren't limited to high-volume commercial environments. On our Kony, for instance, a caked-plane of grounds forms, in the small gap between the bottom of the burrs and above the "revolving door" that pushes out the grinds.
Jim, I'm interested to see how the late/unofficial entry Compak K10 does in your tests. There are elements of the K10 that I and other professional baristas aren't big fans of (doser lid, large grind-chute volume, dosing mechanism), but most agree that the grind/shot quality is excellent. In my experience, it's a fairly close second behind the Robur in overall shot quality.
Again, interested in how this testing develops. Having had extensive commercial on-bar experience with the Super Jolly, Kony, Robur, and Compak K10 (500+ pounds each... a little less with the Kony), I'm intrigued to see how the results of this type of testing corresponds with my less-meticulous, more gross observations.
I bought the K10 for myself based on the feedback at Barista comps, and attractive pricing. For my purposes, it is better designed than any commercial espresso grinder I've owned -- the throat is very deep and perfectly cylindrical, so it is the easiest of the lot to run without a hopper (the throat is, in effect, a working nano-hopper). The grind wheel is easiest to set between espresso and french press, and the throat, while deep, is very accessible. It is also very quiet. The hopper lid is cool looking, but, you're right, harder to remove.
However, I'm not seeing it clearly distinguish itself from the pack yet. I'll try a few more blind tests at lowered doses to see if it shines more at those.
I'm not entirely sure how the assessment of a grinder in coffee shop will differ from one done at home by someone tasting and rating every shot. If you are frequently dialing in different brands of grinder and tasting the shots, I would think you would slowly come to stronger conclusions than anything we can generate. If you primarily use the grinders in service, your conclusions on consistency and packing will be stronger, but those on taste may be equally slim on evidence.
My overall impressions so far are this:
-- For commercial use, bullet proof consistency is what is most important, while the frequency of god shots is somewhat secondary. A home user will be more interested in frequent God shots, but consistency will probably still rank higher.
-- By this criteria, I think the Robur is well ahead of the others. It has been impossible to get a suck shot from it under any circumstance. The grinder performs well at all doses, it packs more easily, and it tastes better if the grind is slightly too coarse or fine. On WBC scoring it's hitting 3.5 to 4 every time, and garnering its share of 4.5 scores. But I haven't had a 5 from it yet.
-- The large Macap is also very solid in terms of consistency, but it seems to be running at a lower quality level, no 4.5 shots at all. My gut instinct is that it tends to run flatter in taste than the others. It may be the grinder of choice for a cafe running a very bright blend; but so far it is my least favorite grinder. I'm also not happy with the chrome body, which somehow looks cheaper than the powder coat on the others; and I'm distinctly unhappy that it's 1HP motor doesn't have a second starting capacitor. A person paying 1K for a grinder shouldn't be subjected to jalopy noises when he or she turns it on.
-- The little Macap responds most linearly and predictably to dosing changes. Unlike the M3 or Mini, it doesn't produce really terrible shots if the dose is too high or low. I rather think people buying this attractively priced grinder will find it a distinct improvement on flat burr ones. The Macap dosers are my least favorite in terms of feel, although they do a perfectly competent job. I've gotten some 5s from this grinder; but it is the hardest of the Titans to pack, roughly equivalent to a flat burr grinder.
-- The Compak is producing very easy to pack shots like the Robur, but is quite finicky on grind setting. In terms of taste, I haven't figured it out yet. I got a 5 from it yesterday; but as one changes dose, it seems to move very quickly from lively to dull shots. More upsetting, in terms of my extraction theory, the shots also get duller as one ups the dose from the sweet spot.
All these conclusions are personal, and subject to change as I amass more data.