1. Overview
  2. The Story
  3. What does it do?
  4. Videos for your enjoyment

Overview

My friend Antonio Nurri in Italy has been involved with coffee for as long as I have known him. Always pushing the boundaries, he showed me some new Barista tools he was working on. One part of it caught my eye and I suggested that it might be an idea to make the tools modular. The VDT part is what interested me.

The tool is part of a larger system for professional Baristas. The larger system weighs the dose, does the VDT part and also measures the tamping force, storing all this information. The Vibration Distribution part what was intrigued me from almost 2 years ago when he sent me a video of the coffee moving in a portafilter. My interest was because I had tried to do something similar with Dental vibrators and it was a messy failure. The dental vibrators simply don’t have the type of construction or sheer mass to work.

I have been using the VDT as part of my coffee prep since October 2019 and I have tried many other distribution methods and a few tools. They either didn’t achieve anything, were messy and troublesome, or both. Antonio felt the extraction % was better and I tested this. I personally could not find any real difference. With a properly prepared puck and a successful shot vs using the VDT there seemed to be no significant difference in extraction yield. I would have liked it to be so but it was not…I did tell Antonio this.

I think Antonio was disappointed but what I didn’t tell him was I intended to continue using it because there were some things I had noticed and liked. I also was careful to say above that successful shots seemed to extract the same….which is mostly what I expected. The keyword is successful shots. I’ve since been using it with all sorts of coffees requiring many levels grind fineness, when they are young and as they age in the bag.

So in the interest of not leaving the best till last, I believe:

  • It aids distribution within the portafilter
  • It allows the coffee to “climb the sides slightly” improving edge seal
  • It seems to redistribute vertically as well as horizontally
  • It largely eliminates voids in the puck (less soft spots)
  • More successful shots
  • I enjoy using it

OK all the stuff above is what I believe, truly believe. Antonio might be a friend and as a friend the best thing I could do is tell him it isn’t any good, if that’s what I really think. However, I actually believe it is beneficial, I would like to see him start production and make it available at a sensible price point.

The Story

It started almost 2 years ago, as I said before he sent me a small Video and I said you should make that device modular. When I arrived onto the ACS stand at Host 2019 last October, he showed me the Prototype VDTs. They were in a number of finishes, White, Steel and Dark steel. We spent a while glueing in the silicon inserts that hold the portafilters. At the moment the inserts were only for standard size 58mm portafilters…but I am sure other sizes could be made available if it goes into production. There were stand alone Models and ones attached to and triggered by a grinder.

Antonio (inventor) on the right talking to some interested retailers

I’m only covering the stand-alone model, mine is a white one and has seen some action at the show and plenty at home. It’s a prototype so final finishing is only to prototype standard. Getting it home was quite interesting as it was heavy well wrapped and had a spare motor with lots of wires, the Italian airport security got quite excited when they put it through the X-ray system. I had it in hand luggage as I didn’t want it to get broken and it was really heavy! I got it back home and testing began

My friend Mark Burness from the forum drove the refractometer and together we did some tests that showed no significant extraction % differences. I trust Mark and have accepted those conclusions. Admittedly it was a small series of tests, wasn’t on pressure profiling machines or pushing the extremes but many purchasers won’t do that either. Perhaps at the pointy end it will make a difference…who knows, just something I’m not prepared to claim. I decided to keep using it….because there seemed to be something there. I have had quite a few questions from people who saw it on videos asking, what is that, where can I buy it, does it work and have not said anything much until now.

In fact Antonio himself probably thought I had given up on it when I said it didn’t seem to increase the extraction % in my tests…but that wasn’t the end of it for me. I’ve been quietly using it for months now and I like it!

What does it do?

Not sure, but it does something. You might be shocked at me saying not sure but reading the scientific literature on agitation, vibrations fluidisation of particles there seem to be conflicting theories.

Unlike conventional solids, liquids, and gases,
binary granular mixtures separate when agitated. By
vibrating binary granular mixture, the large particles
usually rise to the top of the bed, resulting in the
“Brazil Nut” (BN) separation[1,2]. By varying the
vibration parameters or the particles’ physical
properties, the large particles also can sink to the
bottom, resulting in the “Reverse Brazil Nut” (RBN)
separation[3].

Chuanping Liu,+, Lige Tong, Shaowu Yin, Peikun Zhang, Li Wang*,+
School of Mechanical Engineering, University of Science and Technology Beijing, 100083, China
Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, 30 Xueyuan Road,
Haidian District, Beijing, China

So the particles might go up, they might go down and with the VDT they’re obviously going round and round as well.I looked at lots of papers and they really left me none the wiser. So for the VDT I went with my gut.

The gut feel is a highly non-scientific but effective process of mine. If something is a waste of time and not worth using usually after a few weeks or months I give up on it as I did with my cheap knockoff distribution tool tamper thing. The VDT has been on my bench for 5 months with only a brief spell of 2 weeks off it. I’ve used it all the time and after a few weeks I missed it not being on the bench.

I’m convinced my shots look better and are less likely to channel (especially with difficult coffees like the El Salvador in the video (needs a really fine grind). If they look better, and don’t channel they are likely to taste better.

Can I offer you science, no, because I’m not sure the science is out there. Do I think sorting particle size in the portafilter is a good idea, instinctively I do as we get a more consistent coffee bed in the puck. Others may disagree but my personal experience of the VDT has been positive..

Things I’ve learned:

  • Don’t grip the handle too tight, just 2 fingers.
  • It weighs over 3.2Kg (needs to be heavy to work properly).
  • I should try the different shore hardness vibration plate mounts (in the future I will). It might make a useful accessory option.
  • It takes a little practice to use.
  • It’s best the coffee is in a conical mound, or fairly flat in the portafilter, gets you off to a good whirling start with no spill over.
  • Don’t overfill the portafilter.
  • Allow it to glide around the counter like a little Dalek, it doesn’t matter, restraining it only makes it angrier.
  • Don’t tamp with the portafilter in the VDT, it’s not designed for that
  • Only use it for coffee!

Here are some Videos for your enjoyment:

This is an overview of the tool after using it for the last 5 months

An earlier video

Workflow & non profiling shot
A conical pile of Coffee from a Eureka Atom Speciality 75E flat burr grinder

Conclusion

So all I have are some videos of the VDT in action, you will also see it on many recent videos of other things during the last 5 months. You have to make your own mind up.

I can’t offer you science because I’m not sure it’s necessarily there, I don’t want to give you some marketing BS because it’s a prototype and not even a product yet. I don’t believe in hype, I like facts. This is one rare moment when I don’t have many, I just have to go with my gut and what you can see on video.

I think it works really well with bottomless portafilters and since the prototype the current batch of VDT devices has had the internal diameter increased so that all portafilters are suitable

The facts I have:

  • It definitely grades the coffee by size
  • Definitely removes most or all voids and low density areas in the puck
  • I think 10 or 15 seconds is optimum time to vibrate coffee
  • The coffee spins and dishes in the portafilter (this seems good for edge sealing)
  • It forms little balls on top which disintegrate when you touch them, more so on fine coffee, I don’t know why.
  • Higher success rate for shots
  • Shots seem to hold together longer (observed on a naked portafilter)

I like it, a lot and it has become a regular part of my shot prep. I hope when Antonio reads this he finds a way to get this to market at a price people can afford. If it’s not too expensive, what have you got to lose. You can find Antonio at the link below:

https://www.facebook.com/antonio.nurri/