Laser particle sizing analysis: comparing the grind distribution of some top filter coffee grinders.

I’ve had grind samples from some of my coarse/filter grinders at home and at work analysed a couple of times over the last year, via laser particle sizing, and have just submitted a new batch of samples which focus on some areas currently of interest to me. This is made possible by @mathewsmith1 who is absolutely awesome for taking the time to make this sort of analysis available to me.

I’ve posted in the past more detail about the specific nature of the particle sizing conducted, and some of the related topics, and this is available in previous posts on the blog. I find the process and the information both fascinating (fun!), and illuminating. It helps to inform and reinforce all the other information I gather and write up about my brewing.

This time around, I wanted to hone-in on a couple of grind settings on my filter grinder at home, a Mahlkonig Tanzania. Specifically, I wanted to look at a couple of settings around a medium drip grind that I use for some pourover brew methods, and some settings close together right up at the coarse French Press end of the scale.

I have built and fitted a weighted hopper modification to my Tanzania to minimise and counteract any possible effects of ‘popcorning’ when single dosing (effectively eliminating it), and optimising the grind as much as possible, I believe, whilst also keeping grind consistent regardless of dose/batch size.

And, I wanted to assess and compare the particle size and distribution curves of a sample from the plan cafe’s fairly new drip and FP grinder, our Bunn G3, with my modded Tanzania.

The Bunn is a well-known drip grinder that is widely used within modern speciality coffee circles, especially in the US, and it’s fairly highly regarded. Admittedly, the stock, pressed, burrs are not nearly as handsome as those on many other top-end modern coarse grinders, such as the Tanzania, etc, but, there are certain features with the Bunn that help to mitigate and overcome this. I suspect the Bunn might still display a less ‘optimum’ curve than the Tanzania in some ways (it should do anyway, although I could be wrong). But, the Bunn does make some very tasty coffee all the same (which raises other questions about what is actually optimum, and how this affects brewing …another topic).



Then, a local coffee enthusiast, Mukhtar, approached me with news of his newly acquired Hausgrind Made by Knock hand grinder, and expressed interest in having the grind laser analysed.

I had already heard about the Hausgrind. They are one of a few new hand grinders coming out recently (like the OE Lido and Lido 2 for instance) that have been specifically crafted to produce exceptionally uniform grounds in the medium to coarse range used for filter and FP methods – and which are potentially comparable to the top commercial electric grinders, like those mentioned above (along with the likes of the Uber, EK43, Dittings and other Mahlkonigs) (and with Varios with special steel filter burrs, and certain other Mahlkonig models, offering an option at the top-end of the domestic electric grinder range). The samples I’ve seen, and tasted, from his Hausgrind seem really very good indeed.




So, now, this has happily developed into a nice little comparison of some of the top coarse grinders out there, both commercial, and domestic hand-driven!

In the end, we almost coincidentally selected the exact same bean for our samples, and, we’ve followed pretty much the same protocol, to standardise our samples, which has worked out brilliantly, as this will now make for an even more direct comparison between the grinders.

Some of my (edited) notes regarding my samples from the Tanzania and the Bunn:

Suke Quto washed Guji light filter profile from JGC.

Roasted 27/03/14

Samples ground on 6th and 7th April 2014 (1 additional sample added ground on 13/04/14)

All samples 20g, in order to accurately replicate the grind profile/distribution produced by the grinders for an actual small batch size.

5g of Suke Quto purged through on each new setting before taking sample.

Samples ground directly from Tanzania into the press-seal plastic sample bags.

As per my standard practice, with Tanzania, beans loaded onto static burrs, weighted mod applied, then burrs switched on. For Bunn, beans are dumped into already running burrs, again as per my standard practice for this grinder.

Matt mentioned he might even run analysis on a sample from his own Hario Skerton hand grinder as well (which is not in the same league as the other grinders, but which is a nice enough little entry level hand burr grinder), which would be great to compare alongside the others as well.

Samples will be tested using a Malvern Instruments Mastersizer 2000 laser diffraction particle analyser, to produce grind particle distribution graphs and data.

Other recent news:

My recent espresso selection at the plan cafe has been: JGC’s Naturelle (composed of Santa Maria natural and Daterra Special Reserve organic Brazils, with Suke Quto washed Guji), and also Formula 6 (30% Fazenda Samambaia, Brazil 100% yellow bourbon, 30% Fazenda Sertaozinho, Brazil, 16% Guatemala Conception Pixicaya Lot #1, 16% Guatemalan Finca Cuxinales, Genuine Antigua, 8% El Salvador Finca Suiza Micro Lot).

Filter profiles available for beans and French Press at the cafe have been JGC’s Finca Zarcero Costa Rica, Fazenda Samambaia, Tanzania Blackburn Estate Pick of Harvest SUN, and a personal favourite, Suke Quto washed Guji filter profile.

We’ve also seen two coffees from pioneering coffee agronomist Graciano Cruz’s Panama farms, Los Lajones and Emporium (Caturra), via Union Hand Roasted’s light roasts. Both natural process, and exhibiting variations on lovely ripe fruit, like strawberry, blueberry, orange, pear, and wine, translating into various fruit sweets (like Starburst!). Very well processed, ‘clean naturals’, as you’d expect from Graciano’s designer coffees. The Emporium Caturra microlot is currently available, right now.


I’ve also been enjoying some filter profile samples of new Colombians at home, like Finca La Primavera, and look forward to seeing more of these soon!


Oh, and yes, it’s true: The Bean Vagrant and better half have had an amazing, bouncing, beautiful baby bean of a boy, Tom!! Welcome to the world! 8-D












4 Responses to “Laser particle sizing analysis: comparing the grind distribution of some top filter coffee grinders.”

  1. strevethyen Says:

    Reblogged this on C8H10N4OTWO and commented:
    A blog post on espresso grinders coming soon, however this is a good little analysis of filter grinders.

  2. Jordan Says:

    A year on but the results from the analysis still have yet to be posted? I would really like to see the data!

    • thebeanvagrant Says:

      Yes, it was never my intention to publish all the data, and I have no plans to at present. The results are much as one would expect, and are similar to other research that can be found online.
      There is however a run down of the essential findings from this particilar batch of tests in the next post above.

  3. thebeanvagrant Says:

    Please note the graphs for the laser sizing results can now be found in the next post above 🙂

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: