Dosing and resultant puck with the IMS screen

GeekKopi

Well I've had the IMS shower screen for a couple weeks now and I have noticed that my puck is drier. This is with a 18g dose with a synesso basket.

With my vbm screen there was always a tiny amount of water sitting on top of the puck when I pulled the PF out of the group head. With the IMS it's dry, no puddle and looks "beautiful".

The coffee taste wasn't affected but the little bit of water has always bothered me.

Seems the IMS solved that little 'problem' but I'm just curious as to why?

The only way I could eliminate the little bit of water when using my vbm screen was to updose a little over 18grams.

Has anyone got any theories or experimental results regarding this?

I've noticed the IMS screen has a flatter profile vs the more convex profile of the stock VBM screen

Brett H

No idea but I like mine!

Kevohere

I'm sure someone of your vast experience in this coffee world would have compared/measured the distance of the same amount of basket grounds between each screen.  :question: I haven't checked my IMS against the standard Strega screen, but the flatter profile IMS may sit deeper into the group basket than the VBM, thus reducing the "water space" between the two surfaces. The only time I get water pooling is if I've dosed low or ground too fine. Bearing in mind that the Strega being a lever, more water has to pass through the grinds as the spring fully releases. You may have seen this but I found this Matt Perger article helpful: http://baristahustle.com/for-a-good-puck/

GeekKopi

on 1434611693:

I'm sure someone of your vast experience in this coffee world would have compared/measured the distance of the same amount of basket grounds between each screen.  :question: I haven't checked my IMS against the standard Strega screen, but the flatter profile IMS may sit deeper into the group basket than the VBM, thus reducing the "water space" between the two surfaces. The only time I get water pooling is if I've dosed low or ground too fine. Bearing in mind that the Strega being a lever, more water has to pass through the grinds as the spring fully releases. You may have seen this but I found this Matt Perger article helpful: tp://baristahustle.com/for-a-good-puck/

Hi Kevo,  actually the IMS screen is a little shallower compared to the stock vbm screen - so its the opposite of what I expected with respect to the headspace and dosing. So essentially if I had to updose a bit on the stock VBM screen to eliminate the little pool of water then I expected on the IMS I would have had to updose even more due it being shallower, but it turned out I didn't. Somehow the pucks are just dry and this is across a few bean varieties I have at home. so I'm thinking maybe the shape of the screen, flat vs convex comes into this somehow - who knows?... the coffee still taste great.

Brett H

Did you change the basket as well?  I'd be thinking this would have more to do with the basket than the screen... Unless... The IMS drains the headspace between the puck and dispersion screen more effectively??

GeekKopi

on 1434620887:

Did you change the basket as well?  I'd be thinking this would have more to do with the basket than the screen... Unless... The IMS drains the headspace between the puck and dispersion screen more effectively??

same basket Brett. The only variable is the screen. Interesting thought regarding draining the headspace.

steve82

On the Mara e61, I can dose a lot higher than the stock screen. 18g / 18g VST used to always get to close / touch the stock screen and extractions were not that great unless I dosed 16.5 - 17.5, pucks were always wet. IMS I am usually dosing 19 - 19.5g, with some coffees I can dose 20g no worries, still passes the 5c test and naked extractions are even and taste great. Firm dry pucks that knock out with ease. My theory would be that it has something to do with how evenly it disperses nice little water droplets through a much tighter mesh, as opposed to my stock screen (tea strainer) which gushes. So, when the shot / pressure is stopped the finer mesh of the IMS does not let as much or possibly any? little dribbles of excess water onto the puck. Overall it is by far the best value upgrade I made to my machine.

GeekKopi

on 1434687721:

So, when the shot / pressure is stopped the finer mesh of the IMS does not let as much or possibly any? little dribbles of excess water onto the puck.

Interesting.... I might do a test by comparing the IMS and the stock screen if time permits his weekend. Regardless. I'm loving the screen. Cleaning is as simple as a flush as compared to the stock screen where even after a flush I had to brush it to remove remaining grinds.

Cuir Beluga

Don't make any solid plans Geek, you might get a visit of the pink variety  :P.

steve82

on 1434704392:

Regardless. I'm loving the screen. Cleaning is as simple as a flush as compared to the stock screen where even after a flush I had to brush it to remove remaining grinds.

Yeah everything else aside, real or not, the cleaning aspect is worth it alone and clean machines make tasty espresso.

obnic

I found the IMS screen helped to disperse the flow of water from the group - looked more like a rain shower across the whole screen than the flow from a tap from the middle part.  Not sure how this would translate into a drier puck but I did think it resulted in better mouthfeel and possibly a higher extraction yield (but I ever did enough refracting to really prove that or not). However... they are not very strong.  I had to get a replacement after damaging one with a pallo group cleaning brush.

Brett H

Hey, that's really good info Obnic!  I'm going to grab a spare!  I wondered if they were robust.