Grinder Tech - Page 2

Grinders are one of the keys to exceptional espresso. Discuss them here.
Paroxysmalism

Postby Paroxysmalism » Nov 25, 2017, 10:39 pm

namelessone wrote:We did attempt to do some objective comparison using Kruve (see the thread Kruve coffee sifting for drip/pourover) and Vario had more uniform grind than the hand grinders we tested (Feldgrind, Lido, Kinu M47 and so on) and I also noticed the same in the cup. Strictly talking about the steel burr set though.


Fair enough based on that parameter, though I'm not sure there's significant consensus on uniformity and particle distribution being correlated strongly/reliably enough to in-cup espresso results, though I guess that's the best objective measure we have. I think, if I recall correctly, some fairly well regarded grinders not scoring so well in that area and some low-end grinders likewise doing well. That said, personally, I'd still consider the build quality, true stepless adjustment, and reliablility of the above hand grinders as clear and substantial wins over the Vario. Whether or not those qualities matter versus uniformity and convenience is another question.

I guess what I'm saying is that I think we should be skeptical about reductionist claims until they are verified. I think that if we pare down 'quality' to one quantitative variable without first verifying this variable as the sole or major contingecy of essential quality, then we run the risk of not truly measuring or achieving quality.
Adam
Single-Origin Alchemist

barneyfife

Postby barneyfife » Dec 01, 2017, 6:16 pm

I notice a few of the respondents have the Kinu barrel grinders and like them. Wish Kinu would put them in a squarish knee mill,...can't stand the barrel format. I think their biggest is a square format, but too expensive (for me).

I'm liking what I hear about the Sette except for the gremlins and Baratza using their customers as product testers. :(
* Couldn't they have insulated that machine for noise? It's like they design from the outside in, as opposed to the inside out, if that makes sense.

timoseewho

Postby timoseewho » Dec 02, 2017, 2:48 am

moomooranch wrote:Using bike tech as an analogy, burr size might correlate to frameset weight while burr design might correlate with aerodynamics.

There seems to be a shift away in focus from sheer burr size to unimodal burr designs ever since the EK has gained popularity, and as the benefits of higher overextraction potential is better understood. Likewise, the aero advantage of bike components are now understood to outweigh, well, weight in the bike world, with manufacturers moving away from trends like squoval downtubes, narrow V shape rims, and leading edge/rim brakes.

Looking forward to 2018 as there appears to be a movement towards low-retention, on-demand specific unimodal burr grinders such as the Eureka Atom Brew Pro 75 and Compak PK 'High Yield Extraction' burrs.

hey, sorry if this is a dumb question, but what's a unimodal burr grinder? does it differ from conical/flat burrs?

kwantfm

Postby kwantfm » replying to timoseewho » Dec 02, 2017, 3:05 am

Unimodal refers to the grind output rather than the type of burrs. A number of years back there was quite a stir in the World Barista Championships with the rise to greater prominence of the Mahlkonig EK43. It was posited that the large flat bulk grinder burrs contributed to the ground coffee being more unimodal in terms of grind distribution with the effect being an increase in coffee extraction yield. Coffee beans are brittle and this means that however a grinder breaks down the coffee the grounds are shaped differently and also of different size. It is my understanding that the general consensus using electron microscopy suggests that conical burrs produce bimodal grind particles (coffee grinds tend to cluster close to two particular grind diameters) and large flat burrs tend to produce more unimodal grind particles (as per bimodal but with grinds clustering to one particular diameter).
LMWDP #602

CwD

Postby CwD » Dec 02, 2017, 3:13 am

kwantfm wrote:It is my understanding that the general consensus using electron microscopy suggests that conical burrs produce bimodal grind particles (coffee grinds tend to cluster close to two particular grind diameters) and large flat burrs tend to produce more unimodal grind particles (as per bimodal but with grinds clustering to one particular diameter).


Note that traditional flat burrs like the Major and Super Jolley do not have a unimodal distribution like flat burr grinders like the EK43 or Ditting. Example graph here: https://www.instagram.com/p/_Ap3iqyuBr/

timoseewho

Postby timoseewho » Dec 02, 2017, 4:09 am

kwantfm wrote:Unimodal refers to the grind output rather than the type of burrs. A number of years back there was quite a stir in the World Barista Championships with the rise to greater prominence of the Mahlkonig EK43. It was posited that the large flat bulk grinder burrs contributed to the ground coffee being more unimodal in terms of grind distribution with the effect being an increase in coffee extraction yield. Coffee beans are brittle and this means that however a grinder breaks down the coffee the grounds are shaped differently and also of different size. It is my understanding that the general consensus using electron microscopy suggests that conical burrs produce bimodal grind particles (coffee grinds tend to cluster close to two particular grind diameters) and large flat burrs tend to produce more unimodal grind particles (as per bimodal but with grinds clustering to one particular diameter).

ah this is a great explanation, basically when a grinder is unimodal, it's a badass:P

thanks!