I have been a user of IMS shower screens on my E61 groups for quite a few years however I’ve noticed that when using a naked portafilter, that beading would take slightly long to for in the centre of the basket and would often result in tripod pours. I’ve done some previous testing around tripod pours and they can be caused by lack of headroom above the puck. There are various ways around this such as down dosing or using slightly thicker group gaskets to achieve more headroom, however I got to wondering if this could be improved on without these modifications.
I was sat around thinking about why this might be happening and dropped the screen out of my machine for a closer look. I noticed that on the IMS screen that there was a significant portion of the screen in the centre (i.e. where the deadspot was forming) that did not allow water to pass through. This made me wonder if the cause of the tripod pours could be related to uneven pressure build up over the puck.
After a bit of googling around for E61 showscreens I came across the KVDW E61 replacement screen (www.keesvanderwesten.com). I believe that this screen is built to KVDW specs by IMS so I decided to give one a go. The first thing that struck me when it arrived was the excellent look and build quality. I especially love the etched logo 🙂
The one thing that I’d seen on pics on the internet was that there was no big void in the centre of the screen.
To illustrate, the IMS screen is on the left and the KVDW is on the right. For me the KVDW screen should result in a more even water flow through the puck, which is what I was aiming for.
After fitting the screen I immediately noticed a big improvement in shot appearance. First thing was that the beading during pre-infusion appeared almost simultaneously over the bottom of the basket which I take as a good thing. I also noticed that I had less deadspots and also the tripod pours were a thing of the past. These things could be due to a couple of reasons but the hole pattern and the fact that the screen is touch shorter than the other IMS basket I believe are the two main contributors.
I’m not a believer in judging espresso based on looks and on the whole I think that changing something like this can only ever result in marginal gains as far as taste goes, however shots have been consistently tastier on the whole since I switch over to using this screen and that’s the main thing for me. That said there is something very pleasing about a great looking shot and who knows maybe even this has a psychological effect on the taste.
KVDW make some amazing coffee machinery so head over and check them out!!