CwD wrote:Some of us, including myself, follow the philosophy that a more even natural (as in not created by sieving) particle distribution is always and without exception better in the cup.

So, what are you saying. You taste the difference, or do you just follow the particle distribution to tell you which is better?

I don't want to pick up a fight, but as a non-English-speaker I find the afore mentioned a wee bit confusing. Apologies for that.

The difference in taste with higher extraction is evident, and the more even the grind the higher extraction can be pushed before astringency. I found this with my own grinders simultaneously owning a K10, Mythos, and Bunnzilla, and believe it can be extrapolated to grinders I haven't tasted that are more even still than my EG-1 like roller mills.

Bigger burrs taste different than smaller burrs, most of the time. Whether the taste in-the-cup is better depends on your own appreciation.

I have a Macap MXKR that has smaller burrs than my Robur, but for some coffee I swear that I prefer the taste from the MXKR.
I have a Major that has bigger burrs than my Mythos and the Mythos give me better results for some coffees.

The MXKR is not good at single dosing and neither is the Mythos (for practical reasons) so I use a loaded hopper for both. I single dose on both the the Robur and the Major.

I honestly do not think that there is a general rule. But I can say that I always preferred the shots from the Major over the Baratza Vario.

CwD wrote:The difference in taste with higher extraction is evident, and the more even the grind the higher extraction can be pushed before astringency.I found this with my own grinders simultaneously owning a K10, Mythos, and Bunnzilla, and believe it can be extrapolated to grinders I haven't tasted that are more even still than my EG-1 like roller mills.

Great point! I never thought of it.

malling wrote:There is a massive difference in how well the Vario and EK's perform. The quality of the burr, the precion and tollerance of the burrcarier and chamber. You might get a grinder where everything is perfect, but then again you might not.

People who has tested EK using Kruve lies between 70% in the middle section to 90% just to point out the varience in quality!

Which two sieves? And how much % lies in between also depends on the grind setting, which can vary from grinder to grinder I think. We've tested quite a few grinders for filter brews but only have one data point for EK43, but it was used for Clever and is a lot finer grind than the other grinders we tested for, so really hard to compare. In general people doing filter with EK43 seem to grind a lot finer than other grinders (probably due to more uniform particle distribution?)

If you happen to have a Kruve as well you can perform some simple tests.

The same Sieve set size (400-1100) and the highest achieved nr. in the brew range (all those I have seen is between setting 5-7, vary because of 0-point etc.)

I only have 400-1200, and end up with 79% between the sieves with Vario in my single brew (15g dose) setting. With Kinu M47, it's 73%. So it's not a huge difference between them, but somewhat noticable in the cup.

I'm not sure it's so much bigger is better but when I went to a Pharos from my Rocky the difference in flavor was immediately noticeable.

CwD wrote:The difference in taste with higher extraction is evident, and the more even the grind the higher extraction can be pushed before astringency.

That sounds pretty much right to me. Thanks for making it clear.

As we all know there is far more to a burr than the outside diameter. The burr geometry, the ID & the bolt holes will all play a part. But a bigger burr will always be better if equally well designed.


Drawing and Chart comparing different burrs

A bigger burr has a much greater surface area which gives the designer far more freedom when designing the geometry. Take a look at an EK burr and you will see it has large finishing burrs (the flat part on the outside of the burr) while on a Mazzer Mini its almost non existent.


EK compared to Mini

The ID has to be of a minimal size to feed the coffee in, this means a small burr will need to have a steep cut profile a Mini has just 12.5mm from the ID to the OD & the burr angle is around 30°. An EK has 22mm which results in a burr angle of 17°. If you look at the 75mm Mythos burrs you may notice that the ID is relatively small, it has a longer grind path than the 83mm major.

There is also part of a burr that has a negative effect on the grind, the bolt holes. On a Mini they take up a large proportion of the burr, 18% of the beans will pass over these holes when they are ground. The holes take up almost 10% of the surface area.

A smaller burr needs to grind a coffee bean much faster to get a dose in a reasonable time because it cannot grind as many beans at once. To do this it must spin an much higher RPM, and have a far more aggressive cut. And its also have a lot less mass. All this combined mean it will increase in temperature much faster during a shot compared to a larger burr.

All this means the designer has greater control over the particle size distribution. Like anything though, sometimes a burr is well designed and sometimes its crap. So small burrs sometimes outperform larger ones. Generally, larger burrs just have too many physical advantages and if the designer is good and exploits these advantages, the bigger burr will be better. If the rest of the grinder is equally well designed, then it will result in better tasting coffee. Don't believe me, just taste a coffee from an EK and compare it to a Mini.

Cheers
Ben