Bottomless extraction always forming first on the same spot

December 24th, 2021, 7:47 am

Hey guys!

I'm having a tough time with my bottomless extractions withmy Rocket R58. Every single one of them the flow forms first on the right side edge near the handle.

My workflow is basically as follows:
Grind 18g of coffee with Mazzer SJ modded for SD into a dosing cup
Brief WDT into the cup to break clumps
Dump on the 18g VST filter
Another WDT to distribute
Tamping with a self-leveling tamper

I have tried tweaking the dose and grind, to minor results. I have also tried to rotate the filter in the PF to see if it was a flawed filter to no avail. I have tried to purposely distribute more coffee to the area where the flow typically comes first to see if my technique was off, but it didn't work. And lastly I even tried leveling the machine to counter this concentrated flow, but it also didn't help. My shower screen is already an IMS and the waterflow with no filter seems ok to me.

The flavors are mostly alright, but I can't shake the feeling that if I fix this they will be even better

Any other suggestions on how to counter this?

Thanks

#2: Post by **Jeff** » December 24th, 2021, 9:21 am

It wasn't completely clear to me, but have you tried your complete prep through tamp and then rotated the basket in the handle?

#3: Post by **bbobbert3** » December 24th, 2021, 9:45 am

Could you post a video?

December 24th, 2021, 12:10 pm

Jeff wrote:It wasn't completely clear to me, but have you tried your complete prep through tamp and then rotated the basket in the handle?

As a matter of fact, I hadn't try this. I just did and it changed the location, I will run some more tests using this technique to make sure it wasn't a one time thing.

Later today I'll try to post a video

#5: Post by **cafeIKE** » December 24th, 2021, 1:39 pm

WDT in the basket, not the dosing cup.

Grind, dump in cup, rough level, WDT, L E V E L tamp.

#6: Post by **karamba** » December 24th, 2021, 2:05 pm

Maybe your level tamp is not so level?

#7: Post by **Jeff** » December 24th, 2021, 2:26 pm

My guess is the unevenness comes from flipping over the dosing cup.

#8: Post by **karamba** » December 24th, 2021, 3:10 pm

Another thing to check if the basket sits right in the portafilter

December 27th, 2021, 8:54 am

Hey guys!

Just a quick update, I tweaked my workflow and I'm having moderate success. As I suspected from the beginning, the problem is in the most unreliable part, the user

Just for future reference what I have changed from my original workflow is:

No more WDT on dosing cup
Thourough WDT on basket, something like 30 seconds or so, starting from the bottom and slowly raising it until you're just raking the puck.
Remove the funnel and rake again to get rid of the ridge
Vertical tap so you can assess if the coffee is evenly distributed (I believe this is the game changer here). If there is any noticiable unevenness, do some more WDT trying to correct it

December 27th, 2021, 1:26 pm

The only thing I'd caution is making your puck prep too drawn out. Do you really need up to three separate instances of WDT, and 30 seconds to start?

Focus on a repeatable process with minimal variations shot to shot. In a perfect world there is zero variation (not possible for any human).

Personally I only WDT once, about 5 seconds total, with my dosing collar still on. I grind straight into the portafilter.