BZ13 · Espresso · Espresso, BZ13 · product review · Technique

Experience with the OCD coffee distribution tool

ONA coffee released the OCD coffee distributor tool soon after Sasa Sestic  won the champion title in World Barista Championship 2015. According to ONA’s page, the tool was conceived in  2012 and it was used in Sasa’s WBC2015 winning presentation. Check out the presentation video, it is worth the 15-min!


The OCD distribution tool is designed to fit 58mm filter basket. The height is adjustable and the four angled slopes distribute the coffee ground in the basket when the tool spins.

Since the switched to the VST precision filter basket about half a year ago, I have been struggling with bad espresso extraction due to channeling. The problem didn’t exist in the stock basket from the Bezzera BZ13 espresso machine. Don’t get me wrong, I love coffee made with the VST basket. The clarity and complexity in the flavors are more obvious in coffee made with it!

The channeling problem were probably caused by my bad distribution technique (NSEW finger swipe) and the clumps created by my grinder when it is pushed to work much harder (grind much finer) for the VST basket. The following photo shows the clumps created by the Bezzera BB005 grinder.


Before the OCD tool, I had to perform WDT (Weiss Distribution Technique) to get well extracted espresso  without bad channeling. Following photo shows the funnel I created with a disposable cup ‘cut-out’ and a toothpick to perform the WDT in the VST basket. This is the part that annoys me the most in coffee making.


It has been 3-months since I’ve started using the OCD distribution tool. No more WDT, my work flow is cleaner, slightly faster, more elegant and the espresso extractions have been good without channeling majority of the time!

I do not have access to coffee refractometer to measure extraction, you can check out this report which compares OCD vs other techniques and with respect to extraction percentage & taste. I think I am making better coffee than before by the virtue of extraction flow pattern alone, not very scientific and you are welcomed to continue to find out more 🙂

5 cups of espressos were made using the following 3 different distribution techniques.

  1. NSEW finger swipe technique
  2. OCD distribution tool
  3. WDT method

The following equipment/tools were used for the tests.

  • Bezzera BZ13 espresso machine
  • Bezzera BB005 grinder
  • VST 18g ridged basket
  • RB 58mm tamper
  • Hario V60 drip scale


In the tests, 5 cups of 35g espresso were made with 17.5g of light roasted Yirgacheffe Koke. The portafilter was weighted before and after distribution with the Hario scale to ensure consistent dose. About 10-30lbs pressure were applied with the RB tamper.

On a side-note, the alignment between the rim of the tamper and the rim of basket after tamping can be used as a visual indication on the depth of the ground in the basket. When the tamper sits too high, it means the coffee ground will be touching the shower screen. The coffee ground did not touch the shower screen in all tests.


Espresso with NSEW (North South East West) distribution technique

The following chart shows the extraction time and yield made using the NSEW distribution technique. 35g of espresso was extracted in 27s. The chart was plotted with a self-written mobile app which collects data from sensors I implemented in the espresso machine. There will be a future post describing the app and modifications.


The following series of photos shows the flow pattern of the extraction about 10s before the target yield of 35g was met.The convergence to single stream happened 3-5s before target yield was met.


Espresso with OCD tools

The following chart shows the extraction time and yield made using the OCD distribution tool. 34.6g of espresso was extracted in 27s.


Another series of photos which shows the flow pattern of the extraction about 10s before the target yield of 35g was met.The convergence to single stream happened within 10s from the first drip of espresso and continued as single stream throughout the whole extraction time.


Espresso with WDT (Weiss Distribution Technique)

I’ve also conducted one additional test using the WDT method with the same dose to yield parameters. 34.7g of espresso was extracted in 25s as shown in the following chart. I did not make photos of the extraction, the flow pattern was very similar to one made with OCD tool.



So is this for you? I’ll leave the conclusion for you the reader. It solved my bad distribution and coffee clumping issues. I don’t miss the WDT method. And I’ve no idea if the channeling problem would have been solved with a higher-end grinder. The OCD tool is not cheap, and is definitely cheaper than buying a new grinder. Maybe it is made for people with OCD (Obsessive-Compulsive Disorder) who are are obsess with monitoring every shots with the bottomless filter basket! Myself included.

If you are in Singapore and interested in the tools I am using. I’ve purchased them from the following suppliers.

7 thoughts on “Experience with the OCD coffee distribution tool

  1. Hi Chen, have you check Mahlgut Dozer comparing to OCD, what is your opinion? Do you think Mahlgut will distribute better than OCD? I like OCD depth at the ridge/slope, but I think all the ridge/slope should be machined until the end like Mahlgut dozer (without any flat surface in the middle). I think it will distribute even better with that design. I somehow feel 3 slope design is good enough rather than 4 in OCD. I think Mahlgut dozer will be even better if they can design the ridge/slope deeper like OCD. Of course, all the above is just my personal opinion.


    1. Hi WS, I’d love to find out too if i’ve access to Mahlgut Dozer for loan 🙂
      So unfortunately i am unable to answer your question. The OCD can also be better if somehow there are less ground retention on the ridge. Would love to know if that is a problem or not on the Mahlgut Dozer too 🙂


    1. Hi Gary, I’ve not released the App yet. It is to be used together with an accompanying hardware which is described in the latest post titled “Gravimetric espresso mod” 🙂


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