Just a shout out for those who might be interested.

Here's the link:



It was done on a Mazzer Robur E for reference. There's definitely some difference (which makes sense) but not as huge as expected. Personally would love to see the raw data to get a better idea what's happening at <200um and if it was just noise/lack of resolution.

For what it is, it seems like you get an overall tighter spread (not much below 100um and less of the >400um coarse end) with 1kg load in the hopper.

I recall HB did a similar test before but don't think much difference was noticed (maybe due to the use of log x-axis scale?). This was presented on a linear scale.

Update for clarification: All the samples are ground at the same grind setting. No adjustment made. Title's changed to reflect that.

Not as big a difference in distribution as expected but we'll need more test to verify it. This test can also only be used for robur and is not transferable to other grinders.

It will also be interesting to see how a flat burr cope with different usage patterns

samuellaw178 wrote:Just a shout out for those who might be interested.

Thanks! (and I expect the last experiment with the frozen beans will have a less static grind output, but that is not something you are looking for I think)

They do way too much experiments! I just hope they organize all the mini experiments better so it can be pulled out in the future.

Yeah, not grinding frozen beans here. Barely have enough roasted beans.

I am very interested in the results here, BUT I would really like to see some Methods and Materials here. I would fail my year 10 students for that presentation.

I see a continuous line, but bet there are specific sieve sets, so we should be seeing dots, not lines.

I would like some indication on n, how many times was each treatment sampled?

What about the variance?

If there are 10 sieve sizes, I would like to see their sizes somewhere.

Or have I missed a link that gives me everything I want?

Or am I just being impatient ....

T

It's posted on social media (instagram) rather casually, so it's not a scientific piece by any mean. It's more of a glimpse rather than anything conclusive - like doing a whole lot of preliminary tests screening for an interesting topic to dwell into.

As for methods & material, you'd almost have to 'follow' their postings and read the comments, and have faith they know what they're doing.

The gist of the 'experiment' goes roughly like this : vacuum the grinder, load 1kg beans, dial in, (add more beans?), and take a sample for tapping. vacuum, load 500g, dial in and take a sample. Vacuum, dial in with single dosing, and take a sample. It was not mentioned how single dosing was done but it's probably pretty hard to screw up if the effect is really huge.

It's not a full-fledged experiment so I believe n=1 for each. The rate-limiting step seems to be the cleaning & drying steps between using the sieves, and the time taken to fully separate the grinds.

The sieve sets & sizes are mentioned previously, but you have to be patient enough to scroll down...and down......and down....

I've requested for their 'raw data' in the comment section but not sure if it'll be followed up (they get requests and questions all too often and it'd be impossible to fullfill each of them). Granted, I'm not paying them to do the experiments and the results are shared for free (either take it or leave it kinda thing).

samuellaw178 wrote:
As for methods & material, you'd almost have to 'follow' their postings and read the comments, and have faith they know what they're doing.

On their site they claim to do the full peer-reviewed journal write-up, but that seems missing....

T

A full write up would be on their website. They don't do full write up for every single tests unfortunately...

Hallelujah - another hypothesis laid to rest.

samuellaw178 wrote:It was done on a Mazzer Robur E for reference... I recall HB did a similar test before but don't think much difference was noticed (maybe due to the use of log x-axis scale?). This was presented on a linear scale.

I'm not an advocate of single dosing, but if I had to pick a grinder least suitable to the task, the Robur E would be at the top of my list. Many forum members are fans of the Compak K10 Pro Barista because it handles single dosing well. That would be a more interesting test candidate.