Puck screen experience? - Page 10

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Pressino

#91: Post by Pressino »

Thanks, Idfixe! That was an interesting video, especially the discussion about the Weber Unifilter, which sounds and looks really good, except for its $300 pricetag. I've used a straight-walled triple filter basket in a bottomless portafilter charged with 18 up to 20 grams of coffee topped with a 1.7mm puck screen with very good results. I've also got 18 and 20g IMS Baristapro baskets on order for more dosing refinement. The idea of using the straight walled baskets is to provide a larger area of exit holes for the coffee and in theory also get more uniform flow through the puck.

The straight side allows a puck screen to rest precisely on top of a fairly wide range of dose volume and does help keep the puck together during extraction and, along with an IMS nanotech slower screen, ensure even wetting of the puck from above.
Clearly doesn't provide quite as much exit hole area as the Unifilter, but still pretty good compared to "standard" baskets. The bottom of the filter isn't as thick as the Unifilter's, but I'm pretty hopeful that using a 1.7mm puck screen may help limit any filter bottom "bulging," with whatever negative effects that might have (thought the astrophysicist guest speaker wasn't sure they were significant). Also, I wonder if the thicker bottom of the Unifilter (and hence length of the holes) might make it somewhat more prone to getting clogged with coffee grime (including extracted oils).

BaristaBob

#92: Post by BaristaBob »

Pressino, I like your take on the video with Prof. Gagne. His research on coffee flow characteristics has been well received. From one scientist to another his concepts around coffee extraction have been fair, based primarily on fluid flow dynamics. Also, considering the UniFilter, the use of the bottom paper filter probably would minimize the oils and potential clogging of the holes.
Bob "hello darkness my old friend..I've come to drink you once again"

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slybarman

#93: Post by slybarman »

I'm still not sure there is a meaningful difference "in the cup", but after a few more weeks of use, I am coming around on using the screen from the machine-cleanliness standpoint. The group head is undeniably cleaner as a result of using it. At this point, I've mentally baked it into my workflow at this point, so I'm not really conscious of the added steps.

skink91

#94: Post by skink91 »

Being a newbie here I almost hesitate to weigh in, but at the same time... I have to figure this stuff out in some way.

I am using a Silvia and the group head has a massive shower/filter screw that always digs into the top of the puck unless there is a lot of headroom in the basket (I can't even use a double basket with a Normcore screen because I can't lock in my portafilter... no room)

I seem to see much more consistent taste results when I do use the screen, and my suspicion has been that the soupy mess at the top from the puck integrity being compromised by that shower screw is taken out of the equation leading to better end result. Definitely cleaner as well. Fair?

baldheadracing
Team HB

#95: Post by baldheadracing replying to skink91 »

Just a clarification/FYI - in the Silvia, the screw imprinting the puck after a shot is irrelevant as the puck is often sucked up at the end of a shot by the action of the three-way solenoid. You want a very little bit of clearance between the puck and the head of the screw before the shot. (That's a lot less clearance than is needed for a thick puck screen.)

Soupy pucks are usually from too much headspace or a 3-way solenoid water pathway needing cleaning and maintenance. (After each shot, the water from the 3-way should dump into the back of the drip tray with enough violence that splashed water will seep down around the drip tray and pool in the frame, eventually rusting the frame unless you remove the drip tray and wipe down the now-wet frame after every session :?.)

If you want a bit more space to accommodate a thick puck screen, then you can replace the stock Rancilio commercial screw assembly with a countersunk screw, preferably stainless steel. (The jet breaker is soft metal and is easily countersunk with a typical twist drill bit.)
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

skink91

#96: Post by skink91 »

Thanks for that info. I had just ordered a new screen update kit that had a flat stainless screw replacement, so hopefully that will also allow for a more appropriate basket size per dose. Good to know that I should keep looking for other causes of my consistency problems though... thanks!

Shakespeare
Supporter ♡

#97: Post by Shakespeare »

I just received an email on a wait list this morning for the SWORKSDESIGN puck screen. There were 50 available...in a few minutes there were none.
Reasonable enough...put name on waiting list if you want. No other option yet.


boren

#98: Post by boren »

How are these better than other 0.2mm puck screens?

Shakespeare
Supporter ♡

#99: Post by Shakespeare »

boren wrote: How are these better than other 0.2mm puck screens?

Won't say if they are better or worse than the woven mesh puck screens...
These are made in a similar fashion as the Webb Uni-filter and the WAFO baskets. They are solid 2mm stainless steel (24 gauge) with a large amount of holes.
Each hole is 200µm, ( 70um is the diameter of a human hair. Most likely they were laser drilled.
My thinking is that these puck screens were designed to replace the use of paper filters and easier to clean than mesh screens that become clogged. And need special cleaning to remove coffee and oils.
They are sold in pairs.

boren

#100: Post by boren »

Looks good. I too prefer 0.2mm pucks screens over the mesh-style thicker ones. This thread is related: Puck screen thickness