I wish I had the cash to purchase one of each and run them through the testing cycle...

The way I test grinders is setting the grind on each grinder in the sample, using the same roast to extract as similar an espresso as possible. This helps insure I've got all the grinders in the sample group as close to the same grind as possible.

Then I grind a 10 gram sample for each and sort and weigh the particulate into ranges with micron screens. Then compile the data and produce the report.

What I've found with the few grinders I've done this with are that the Mahlkönig ceramic burrs have performed with the smallest range in a sample and higher weights in orientation to the statistical mode.

This is how I view the quality of a grinder. I'd love to have others weigh in as I'm not a stats expert, but this model makes the most logical sense to me.

I do stay away from dosers, I just don't like the whole additional exposure to air and the tendency for baristas to grind away and not purge. Even if you do purge, there's always remaining grounds ready to contaminate the next dose.

In my shop, I use a Mythos and love it for daily abuse, day in and day out. It doesn't have Mahlkönig burrs, but does have a nice 83mm angled flat burr. It's performance based on how I test is comparable to the Mahlkönig burrs, just not as accurate.

Paul


...split from Choosing a grinder from an extensive list; Which one? by moderator...

Marshall wrote:Cleaning the innards of grinders tends, I think, to be a useless ritual that results in the removal from nooks and crannies of old grounds that never touch the brewing grinds (and the refilling of those same nooks and crannies immediately thereafter). An occasional burr cleaning with Urnex Grindz or Puly Crystals works fine for me.

Thank you. Another barnacle falls away.

BeanGuru wrote:Then I grind a 10 gram sample for each and sort and weigh the particulate into ranges with micron screens. Then compile the data and produce the report.

The problem is that not even a laser particle counters are accurate enough to distinguish between small changes at espresso grind levels. Screen sizers can't even distinguish between espresso and fine grinds according to several papers published by Petracco of Illy labs and summarised on the espresso coffee book published by Illy.

It's probably a bit late in the day to be posting this, but the following is a list of manufacturers approved by the Italian Espresso Institute. http://espressoitaliano.org/doc/Attrezz...ficate.pdf Instituto Nazionale Espresso Italiano is an organisation whose main aim is to standardize as well as raise the quality of espresso in Italy.

Macinadosatore is the word to look out for regards grinders.

another_jim wrote:The problem is that not even a laser particle counters are accurate enough to distinguish between small changes at espresso grind levels. Screen sizers can't even distinguish between espresso and fine grinds according to several papers published by Petracco of Illy labs and summarised on the espresso coffee book published by Illy.

Even as crude as the measurements that I do, they still tell me a detailed picture. I don't weigh out past the hundredth's place in Grams, so the granularity of what I'm doing is to provide a reliable source of information that pretty much anyone with an interest could do themselves. Which is what my goal is, make coffee accessible to anyone who wants to learn.

I can ascertain which grinder performs better with just the data I compile. For me that is worth it when I can cross-reference another study.

So in the spirit of an additional source of unbiased information, something the average person can do and my commitment to education:
It's very useful when I conduct coffee classes to run through a test, on say grinders and demonstrate how you can with simple tools see how things work, or not. It brings reality to a class room of students that theory just can't match.

Thanks for your feedback, it's valuable to me. If I'm not learning, I'm dying.

BeanGuru wrote:Even as crude as the measurements that I do, they still tell me a detailed picture. ... It's very useful when I conduct coffee classes to run through a test, on say grinders and demonstrate how you can with simple tools see how things work, or not. It brings reality to a class room of students that theory just can't match.

Really...? We had a member here do detailed research on high-end grinders by using a scanning electron microscope to quantify particle distribution. You have screens that can do that? IIRC, even the tests using the electron microscope were interesting, but somewhat inconclusive. My figures indicate that one click on a mid-range grinder is 0.001" difference in distance between the burrs. On a quality stepless grinder it is possible to get a difference of 0.0005" between the burrs, or even a bit less. Those would be some amazing screens!

You stated, "...using the same roast to extract as similar an espresso as possible.." Similar in what way? Time? Taste? Different grinder designs bring out different tastes in a coffee. I had to change my blend to match my tastes when I went from a flat-burr grinder to a conical burr grinder. And having the smallest range in particle size is not necessarily a good thing. Basketballs and ping pong balls make a very different "pack" than basketballs and soccer balls.

With quality grinders, quantifying by any method other than the taste of the espresso is fairly pointless unless you are designing a grinder, and even then, there is only one bottom line. IMO, the only test to compare grinders is double-blind with many testers and many samples.

I know, or at least I think Tristan, that you don't mean to be coming across as aggressive, but your post seems a bit confrontational. Bean Guy is new here and almost certainly has not gotten around to reading the back story on many of the issues he's commenting on.

Bean Guru there are some on this forum with an encyclopedic knowledge of coffee. There are hundreds of years of collective coffee experience on this forum - much of which is concentrated in a few individuals. Knowledge of coffee aside there are no less few with a deep and profound understanding of the scientific method - knowledge that they frequently bring to bear on this forum, to the benefit of all. There is access to research chemists, software engineers et al who provide insight, intellect and method to the collective understanding of this subject. Bottom line - do some reading before you post - no offense.