There is no such thing as a grinder to be wow or the best out there at the same time for espresso or brew.

The big flat grinders perfectly aligned have a really narrow spot on the gauge to hit the maximum taste/extraction yield for a certain coffee in espresso. Going every day back and forward between different set points is not a good idea, you wont hit the max, sometimes its just a tiny hair between 22% and 24%.

I had different types of burrs, and with the best for brew/filter burrs(best results in taste + EY% by far) I could not choke the machine for espresso (even with different baskets, overdose, nutation, filters, and so on). With a good aligned big flat - ditting - mahlkonig vt6a- and so on you won't be able to do espresso. Same goes for Favorite Zwanger 2A a mill that is wow for brew but doesn't grind fine enough for espresso.

On the opposite side, a wow espresso grinder will grind awful for brew. With my SSP rs- custom geometry low fines burrs when I grind for V60 I get particles all sizes, its terrible. Maybe If I could lower the RPM I could get something better but I don't really care because again, I don't like to switch settings after I dial them in for the best shot on that coffee.

On the left you see the Mahlkonig Guatemala 71mm with Silver knight low fines for espresso, and on the right you see the Guatemala SB 73mm with mahlkonig unimodal burrs that cannot grind for espresso but this is a wonderful setup for brew (better than peak or sweet lab). Both grinders are 2850 rpm, with the same design as ek43 (they are almost identical the only difference is the difference in burr diameter but the Guatemala is faster and stronger).

franklin270h wrote:Essentially yes. I had a spare set of the new style coffee burrs (the recent geometry) and sent it to him to regrind/change the geometry to the old style. I also had them silver Knight coated. He can also convert coffee burrs to Turkish and vice versa. Keep in mind and of those geometry changes are a regrind, so your burrs will be a little bit thinner than stock of course.

The coatings are mostly for longevity. They advertise a difference in coefficient of friction between different coatings, but either way ive seen no particular evidence that it makes a big difference in the grind quality, it just adds durability.

No idea about the cast burrs aside from I heard that he essentially made them to be more reliable/uniform for espresso comparative, basically an espresso geared all arounder similar to high uniformity.

I do feel that with basically any grinder that isn't an EG-1 or Monolith that has a specific focus on it, alignment makes as big if not a bigger difference than do the fairly minor differences in geometry between most of the burr options. The EK is notorious because of the ubiquity of them but this is a problem with Bunn, Ditting, other MK, Mazzer, etc. I'd 100% encourage anyone to focus on that first before throwing a bunch of money at burrs, and if they decide to get burrs later then they'll still benefit from that effort. For filter use, aligned vs aligned, I was honestly happier with the MK new style burrs vs the SSP ultra lows. With the MK burrs reground to the older filter oriented geometry I'm MUCH happier with them vs the Ultra Lows.

Would be great to know how the "low uniformity" compare to your reground MK burrs to old filter oriented geometry...could this be possible for you to compare? Perhaps your friend could lend you a set??

Denis wrote:There is no such thing as a grinder to be wow or the best out there at the same time for espresso or brew.

The big flat grinders perfectly aligned have a really narrow spot on the gauge to hit the maximum taste/extraction yield for a certain coffee in espresso. Going every day back and forward between different set points is not a good idea, you wont hit the max, sometimes its just a tiny hair between 22% and 24%.

I had different types of burrs, and with the best for brew/filter burrs(best results in taste + EY% by far) I could not choke the machine for espresso (even with different baskets, overdose, nutation, filters, and so on). With a good aligned big flat - ditting - mahlkonig vt6a- and so on you won't be able to do espresso. Same goes for Favorite Zwanger 2A a mill that is wow for brew but doesn't grind fine enough for espresso.

On the opposite side, a wow espresso grinder will grind awful for brew. With my SSP rs- custom geometry low fines burrs when I grind for V60 I get particles all sizes, its terrible. Maybe If I could lower the RPM I could get something better but I don't really care because again, I don't like to switch settings after I dial them in for the best shot on that coffee.

On the left you see the Mahlkonig Guatemala 71mm with Silver knight low fines for espresso, and on the right you see the Guatemala SB 73mm with mahlkonig unimodal burrs that cannot grind for espresso but this is a wonderful setup for brew (better than peak or sweet lab). Both grinders are 2850 rpm, with the same design as ek43 (they are almost identical the only difference is the difference in burr diameter but the Guatemala is faster and stronger).

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Thanks for your insights Denis...if you were going to get a grinder for brew / filter ONLY and had budget for anything on the market, what grinder AND burr set would you get? I would be aligning the grinder using the best method if it were required (pretty much anything from Ditting, MK, Compak, etc. as was said will need aligning)...thanks! Ben

EDIT: did you have to totally recondition the Favorite Zwanger 2a Coffee mill, and resharpen the burrs? Do you think it's the burr geometry that makes it so good? And what are your thoughts on RPM for brew / filter?

bytheway wrote:Would be great to know how the "low uniformity" compare to your reground MK burrs to old filter oriented geometry...could this be possible for you to compare? Perhaps your friend could lend you a set??

Ha well he's far from me but we both use the adastra app and have enough back and forth to try and get some ideas. I'm far enough away I can't really do an A/B taste comparison anytime soon.

I'll see if I can get some PSD data though, preferably with the same coffee and roast.

Almost all of the EK burrs, MK and SSP, function similarly. The final section is basically a crushing section rather than cutting. What's different with SSP are the number of prebreakers and the design of the teeth. MK inside and outside have the same # of teeth, SSP burrs are designed where only a certain % of the finishing teeth are engaged with the other side at a given point in time. That's generally more espresso geometry philosophy since grinding fine can choke a motor, and that design lets you have a more aggressive burr profile than if you had all the teeth engaging at once.

I think what's happening with say the High Uniformity burrs, and pretty much all of his multipurpose ones of that design, is similar to if you passed a 2x8 board through a wood planer. There's this relatively long, flat finishing section with very shallow teeth and thus a very small channel for coffee to pass through. They're basically designed so the coffee bean "has" to be smaller than "x" size or it's not getting through, the only way anything big would get through would be via poor alignment or distortion of the burr itself. Of course one could say that's how flat burrs work in general, but in the case of fine grind oriented and turkish burrs the entire finishing section is extremely flat, almost like a tunnel. Eliminates boulders almost entirely, but to do so requires more revolutions and essentially more super small fines are created that are harder to measure due to the limitations of every method available at the moment (sieves, laser, apps, etc). The result is unimodal but at the same time, there are plenty of fines. In espresso that's puck structure. With pourover/batch that's often a choked filter. Which with my 80mm bunn SSP burrs the brew times are generally almost a minute longer than say Dittings, if not more especially with dense coffees, and often less clarity as result.

With Low Uniformity and other designs with deeper finishing sections, there's generally less of that and there "should" be fewer fines as a result, with probably a slightly wider particle spread. I've not seen anyone that used both older MK burrs and High Uniformity that preferred the SSP for filter, where for espresso that statement is flipped in favor of SSPs. Low Uniformity ones may change that. Someday the curiosity bug might bite me and I'll trade for some or get some. In my case esp after meh results with the Ultra lows, I got tired of navigating through all the confusion and decided to go with a known quantity, which the old geometry MK burrs deliver on filter in spades.

I have yet to see any data that burr geometry affects % of fines by weight at filter sizes? Coarser grind = less fines. I've yet to see some actual difference that's can't be accounted by average grind size.

Then why I get such different type of grind using the same 2850 RPM for v60/brew with 2 different geometry?

This is the SSP low fines for espresso I am using, and it does bad at filter range. I get big chunks and tiny ones. Fines are to many.

Maybe it has something to do with the speed that the beans stay inside the burr chamber? As for 20g for espresso grind it takes 1 second. For filter/v60 grind it takes less than 1 sec. No time for the beans to get crushed even.

But with the original filter burrs that you see in the second photo I get a really even grind for filter. So what is it? The geometry, the way the edges hold the beans while rotating, the finish of the burrs (red speed versus normal?) they have different friction.





As @bytheway people are different, and they want different stuff from grinders. Some like the utility and the silence that a hand grinder makes, or the fact that is compact, and has low retention. After going and trying many grinders for my personal taste I find a small 200-250W grinder with 50-70 mm ghost burrs perfect. A more expensive example would be the Fuji Royal, but there are many others china grinders that do well even with the lightest roasts out there. I am using a Xeoleo for more than 8 months, 60 mm ghost burrs, zero retention, 250W, grinds 20g for aeropress in 2-3 seconds. It's 1/4 the size of an ek43 and it performs better. It's 1/10 of the price of an Ek.

This is the grinder uncleaned after ~ 4 kg of coffee.

Hi Denis, how do your espresso burrs compare to the SSP high uniformity and low uniformity burrs for the EK?

(Edit: low fines replaced with low uniformity)

I cannot compare them since ek43 has 1400rpm and Guatemala has 2850 rpm.

I hit the same high EY max numbers as my friend (on the same roasted coffee- same batch/date) with ek43 + SSP low +aligned to under 5 microns + Titus carrier. So the grinder is not a concern or a piece to upgrade in the future.

namelessone wrote:I have yet to see any data that burr geometry affects % of fines by weight at filter sizes? Coarser grind = less fines. I've yet to see some actual difference that's can't be accounted by average grind size.

Even my SSP ultra lows have a dramatically different particle spread compared to stock EK burrs. I'll try and get the graphs I have of mine, I swapped hard drives and would have to dig them up

It's not just median particle size either. Matched to the same particle average the spread is way different on just those, not even counting something like an espresso design that's far different. The clean good tasting EY I was able to hit w either was different as well

Fines are relative too and would depend on how someone defines them. For clarity on my end I generally mean particles either way (fine or coarse) that are a much different size than the median target. Sieving for that isn't very precise. If one isolated to say the 400-800 range or 1200 range, really that doesn't tell much because the difference between 400 and 800 or 400 and 1200 is huge in terms of surface area of the particle itself, not even counting how many fines stick to larger particles

By fines above to clarify, I mean any generally excessive amount of particles far different in surface area to the median particle size. And with boulders, the opposite.

When referring to a grinder at filter range making more fine particles I don't think you can limit that to only being super small fines that would escape through a sieve or similar.