The latest & scariest distribution tool - the Duomo EIGHT!

The latest & scariest distribution tool - the Duomo EIGHT!
Karine Ng

Despite looking like something out of the Death Star laboratory, the Duomo Eight actually hails from Korea. And what this sinister-looking coffee distribution tool can do for your espresso is scarier than its looks (and that’s a good thing). 

Hello, my name is Karine Ng. My background includes 3 x Canadian Barista Championship Finalist, and Quality Director of Phil & Sebastian Coffee Roasters. I introduced the Duomo at the Canadian competition stage this year, after it was adopted into our training program and cafes. I’ve never been more impressed with a tool that was able to improve the quality of espresso with results that I can see, measure, AND TASTE. The results are immediate and consistent. So I’m here to provide the Eight Ounce fans with an introduction to the Duomo, and some insights based on my working and competition experience with the tool!

What is the Duomo?

An effective coffee distribution tool for espresso brewing it evenly distributes coffee grounds throughout the filter basket (as opposed to surface-only distribution) to achieve an even extraction.

What is the result?

  1. Taste: An espresso that is consistently and noticeably rounder in mouthfeel/texture, and more harmonious than espressos without distribution, or not distributed using the Duomo. It also often leads to higher and/or better sweetness.
  2. Visual: (imagine looking at a bottomless portafilter) Simultaneous beading of espresso at the start of extraction every time, meaning water is passing through all parts of the coffee bed at the same time/rate.
  3. Quantitative: Calibrated to the correct height, it gives very consistent and easily repeatable results between shots - *TDS of 0.01% variance (*10 shots of the same coffee extracted with the same parameters, and consistent tamping with PuqPress)

Who it’s for:

  • Those who are keen on improving their espresso quality by that extra 15-20% (qualitatively speaking)
  • Those who are looking for a distribution tool that gives even extraction that consistently translates to taste

Who it’s not for:

  • Those looking for swift and easy solution to espresso quality on a very fast-paced bar 
  • Those who are not careful 
  • Those who are in need of upgrading their espresso grinder (ie., grind particle consistency will still give you a higher return when investing in tools for quality)
  • Those with non-commercial sized double-shot baskets (see tech sheet for specific measurement)

More background and detail:

Last year, Phil and Jordan, our trainer at Phil & Sebastian Coffee, were interested in finding an effective distribution tool for our training program. The idea was to simplify our current technique of manual tapping/knocking. From what we’ve seen in our training program and in our cafes, the technique has been effective, but it is also time-consuming to learn and perfect. This means it is difficult to translate to a level of consistency we were striving for in our cafes. After testing several different tools, we found the Duomo was not only easier to perfect, but also exceeded our previous ability to distribute evenly and consistently. 

The tool was built around the Weiss Distribution Technique you can find the original method here. The Duomo is a much more swift and clean WDT tool. It also replaces WDT’s erratic stirring with a controlled stirring pattern that reaches all parts and depth of the coffee bed - achieved by the strategic placement of eight pins with specific thickness for the job.

Before we launched it in our cafes, our trainer tested the Duomo extensively against other popular tools (OCD and BT Wedge) and a cheaper copycat of the Duomo (which is now a very expensive paperweight). The results showed that both the OCD and BT wedge are able to reduce channeling after manual-knocking technique. However, both tools yield significant differences (statistically) in TDS% between shots of identical parameters. This means both tools provided significant inconsistency shot-to-shot, and that neither tool was able to achieve the same shot-to-shot consistency as the Duomo


  • If not used with care, the pins can bend or break off even losing one pin makes a big difference (Replacement parts are available for purchase)
  • Cost
  • One size only  


  • Aside from what was mentioned earlier, the tool has a great weight and feel in your hands, all metal components 
  • Comes with a stand with brush built in, making cleaning grinds off the pins super easy

How to use it for the best result:

  1. Calibrating to your portafilter basket properly is key as deep as you can go without scraping the bottom of the basket. 
  2. With coffee grounds in the portafilter basket, place the Duomo directly on top of it
  3. A slight push of the top, the handle that was held up in place by internal magnets will then drop, lowering the pins into the coffee bed.
  4. Turn the top 3 -5 turns (0.75 - 1.5 revolutions) 
    1. This is what I’ve found to work between stirring enough but not too much (counter productive). Different amounts of coffee and different levels of clumpy-ness in grinds may affect the number of turns you use. 
    2. Controlled turn speed is important too much spin will be ineffective.
  5. Gently pull the top back to its original position (If coffee spills when you remove the Duomo, you can--while securing the Duomo--give the portafilter a light tap as flat as possible on the counter to settle the coffee before step 5)
  6. Lift the tool straight up and place back on its stand.


Questions or comments: 


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