Is anyone using a unique espresso grind distribution technique?

(joe ) #1

so we’re now beyond the results of the great distribution tool debate. my question is, has anyone been experimenting with their own distribution techniques and finding positive results?

i have recently been logging the tds and extraction of shots pulled to varying times and yields. i noticed a surprising amount of variance in the trending differences, even within one batch of coffee, having measured equal doses within a hundredth of a gram with an ohaus scale, having used consistent-as-possible hand tapping as distribution and having syringe-filtered the samples with vst espresso filters before refracting. the results were consistent enough to be useful to me, but i attribute a fair amount of the variance to uneven extraction. i’m sure some of that variance is in the nature of refracting espresso, but it seems obvious through experimentation, tasting and through reading the works of others that an even extraction is not only important, but is not very easy to achieve. for one thing, we are probably getting both over and under-extracted flavours simultaneously from our less than evenly extracted shots.

it seems an even extraction is likely happening when the espresso first starts to ooze out of the bottom of the basket everywhere simultaneously (for those of you with naked or bottomless portafilters). and this is probably only achieved when there is a perfect coffee density throughout the puck. further, a perfect density is achieved by the loose grinds literally having to be somehow evenly distributed throughout the basket before tamping, because an even tamp alone could still allow pillars of denser areas below it.

there are some distribution methods that smooth out the surface of the grinds, like the ocd tool and stockfleth’s method, but they seem to leave the lower grinds unaffected. as of yet, tapping the sides of the portafilter with the palm of the hand while sort of tilting the basket away from the tapping seems to be the most effective distribution technique that the world is aware of. perhaps hand tapping followed by the use of a surface tool like the ocd is even better, but a relevant matter is that hand tapping is probably not consistent from barista to barista, even within one shop.

our shop is curious about the possibility of a platform that holds the portafilter with the basket level and vibrates with almost imperceivably small, but fast and aggressive motions. this may not be practical in a more high volume shop but we shouldn’t let that stop us from experimenting, learning, and sharing our findings for others to build upon. something like a vibration tool that is successful in producing an even extraction might inspire something that is quicker to use, like a grinder that holds and vibrates the portafilter as it fills the basket.

perhaps an overlooked area of distribution has been how grinders distribute the grinds into the basket. i am currently building a prototype of a tool that fits between our grind chute and the basket, with the intention of distributing the grinds somewhat evenly right as they fall. i am planning on still having to do some hand tapping, but at least i won’t have to start by toppling a center pile. perhaps half of our current distribution time is used just getting the peak of this pile down below the rim of the basket. when an even distribution is the end goal, it is less than ideal to start with a peak in one area. i will be sure to share my prototype findings here.

there is a lot of forward potential in the field of espresso grind distribution, and discussion and sharing of theoretical ideas and findings is the way to get there. so if we have any other ideas, or have discovered something useful aside from the common surface tools, hand tapping, or stockfleth’s technique, let’s discuss it!

(j l) #2

So… shouldn’t admit this in public… But I bought a tuning fork and applied it to portafilter.

I think I need a bigger tuning fork.

(Nathan DeRuvo) #3

I haven’t tried this but you would think at least one grinder manufacture would have tried something like this.

(joe ) #4

a tuning fork is a very interesting idea. it reminds me of something i once saw, about specific frequencies of vibration organizing loose iron filings on a flat surface into specific patterns.

it seems that after the initial strike, the majority of the vibration would be seperated from the basket and only in the fork? perhaps you’ve experimented with this?

also, which note did you choose?

(joe ) #5

i’d be interested if anyone has tried this!

(moominpapa) #6

I’ve been using a flour sifter for some time now, basically acts as a single-serving doser

(joe ) #7

okay i’m very curious about this. in an early prototype i tried a chute to the basket with a screen in it, thinking this would break up the coffee density as it fell. even with a coarser screen of about 3 mm openings, the coffee would not fall through and required about a minute of tapping to get it to pass the screen.

how long does this take?

do you measure your dose before or after sifting?

does it result in crisp or juicy flavours?

the reason i ask the last question is i would be concerned that the sifter is further breaking down the particle sizes when it rubs the perfectly sized grinds against the screen.

thank you!

(moominpapa) #8

This isn’t my video, but you can see it in use at around 1:15

I am but a home barista so am not well qualified to answer all your questions. All I can say is that it leaves a really nice, fluffy and clump free coffee mound that can be palm tapped level really easily.

(j l) #9

Actually will get a couple of seconds of “useful” vibration transmitted to the portafilter once it is touched by tuning fork.

Frequency of tuning fork was 128 C. This was just a pilot to determine feasibility, there was not observable change in grind appearance inside portafilter after test so did not pursue.

Though can use an android app to measure resultant tone from hammering the portafilter, and then find a tuning fork to match frequency so then resonance can be a possibility?

No doubt, this could be made to work(sound application to uniformly distribute grinds), but beyond my available time.

(joe ) #10

cool, thank you for this!

(joe ) #11

distribution by sound and vibration could surely use more investigation…

(Troy) #12

Totally agree. I’ve been thinking about a device to distribute into the basket while grinding. Haven’t progressed to making one yet.

I have seen a 3D printed sifter style device to fit a PF, that looks effective.

It was discussed here previously in this thread.