John49 wrote:A small amount of water leaking over the shower screen should not be a problem, it's just a friction fit. The group seal looks odd it should be black and completely set in the groove provided. The portafilter basket should set it in this groove when engaged.

vis à vis water around shower screen, that does seem to be a non-issue; however, one peculiarity with this is that my shower screen fits pretty darn snuggly. it snaps into place and seems very locked in, and its surprising that water would just drip out from the sides with no piston pressure, i.e. just opening the valve.

IMAWriter wrote:Yes, odd seal, and should not appear as id does.

well gosh darn it. i sent this pic to wouter via email and i'll report back with his words. i have no idea how long its been like this, and i only noticed it when i was meticulously inspecting the machine for no apparent reason

to John49's and Erik's comment, i actually think the camera flash makes the seal appear lighter than it is. in normal light it looks pretty dark/black to me. i bought this machine new in february 2018, its only a few months old now and nothing about it has been modified from wouter's factory standards.

just to describe the group seal pic a bit more, it seems to be pushed too far up into the slot for roughly 1/4th of its circumference (the part which is directly beneath the electronics housing). what i don't get is how/why there is extra room in that slot for the seal slip up into.

any who, thanks everyone for sharing your thoughts on this!

Chris, if you're performing regular maintenance, that seal should be popped out every month, or maybe 100 shots. The piston should be pulled, the seals lubed with Dow 111. Do NOT lube the group seal. Inspect the group seal for any tears.

Hi Rob,
That does seem totally reasonable, and i've done the piston cleaning and green seal lubing bit a couple of times; however, I do not see any mention of removing the grouphead seal on the CT1 maintenance page: http://strietman.net/care-maintenance/.

Nor do I see any mention of it in the CT1 User Manual which came with the machine. However, I do see the following note in the Troubleshooting page of the user manual:
"If the machine leaks water from underneath the brew group during extraction, the grouphead seal should be replaced. SEE MAINTENANCE PAGE."
Hehe but no mention of this process at all in the maintenance page i'm afraid. At the end of the day, I'm just not sure how to remove the darn thing carefully. Still waiting to hear back from Wouter, and i will post as soon as I do hear back!

To remove the group seal, you will need a small flat head screw driver, the sort you would use to tighten eye glasses. Work the driver along the outside edge of the o-ring and pry it out of group. You may need a second screw driver to work around once you've created an opening. Be careful not to damage the o-ring.

(#92 reporting in :^) Thanks for laying this out clearly -- I was looking at the group seal earlier pondering the safest way to pop it out!

For me, it usually just pops out when the group screen does. if it doesn't I can pull it out with my fingers. Soaking that screen in Joe Glo 10 minutes, good as new.

I pull out the screen every other day and clean it with hot water. I also lube the piston seals every other week which takes around 5 minutes once you've done it a couple of times.

Maybe Wouter uses another grouphead seal or the flash in the picture made it appear to be a different color. If it's a brand new machine you should be fine.

erik82 wrote:I pull out the screen every other day and clean it with hot water. I also lube the piston seals every other week which takes around 5 minutes once you've done it a couple of times.

Maybe Wouter uses another grouphead seal or the flash in the picture made it appear to be a different color. If it's a brand new machine you should be fine.

John49 wrote:To remove the group seal, you will need a small flat head screw driver, the sort you would use to tighten eye glasses. Work the driver along the outside edge of the o-ring and pry it out of group. You may need a second screw driver to work around once you've created an opening. Be careful not to damage the o-ring.

thanks for the responses guys. i heard back from wouter today and he said the following:
"Yes with the shower screens there will always be a little water escaping through the sides when its installed.. nothing to worry about.

And the O-rubber is nothing to worry about either, there is air trapped behind the seal, which will push it down when the filter basket is not attached. Will probably settle eventually..."

UPDATE: wouter also wrote back saying that when the filter basket is locked in, the o-ring is forced into the same height/position throughout the circumference. no need to take it out or fiddle with it or replace it. so i will not be tinkering with the o-ring today!:)

i just got an Ethiopian SO light roast from a local roaster, roasted on June 27th, and i cant seem to get a good pour/extraction no matter what I do. I first tried on July 4th, then yesterday, and now today the 6th, and always with the same result: very early blonding, thin & translucent extraction flow, almost no crema, and the taste in the cup is quite watered down.

not sure what to do. ive tried going 18.5g coarser grind (18g basket), as well as 15g finer grind (15g basket), but the result was more or less the same. i will film the whole thing tomorrow and maybe you can give your opinions.

to describe the extraction a bit more: i give it about 8-10sec of light active pre-infusion until i see beading and then i gradually ramp up to maybe 7-8bar or so. the lever resistance is quite hard during the first several seconds of extraction and lets up gradually throughout the pull, and the stream never gets thick, it just goes from thin and brown to thin and translucent/watery.

maybe this coffee only works with a 1:1 ratio? maybe i need to increase temp settings? not sure...
i will post a video tmrw! and thanks in advance for any input!

What does the espresso taste like?

A few thoughts.. If the shot is "choking" for a few seconds post-preinfusion after ramping up to full pressure then perhaps you can try either 1. Extending the preinfusion even longer. Upwards of 15-20 seconds. Make sure the puck is fully saturated and you're getting some drops. Or 2. Make the grind just a touch coarser and keep the same dose and preinfusion parameters.

Is this your first go with the light roast SOs? Keep in mind they don't produce the prettiest extractions. You should be getting a single stream without any spraying or crazy channeling, but you won't get very thick goopy cones the way you would with a darker roast. So don't let the sight of a thin stream convince you that the espresso won't taste good. But the color perhaps is a different indicator. Getting lighter towards the latter half of the shot can happen but if it's happening very quickly or becoming a clear watery stream then perhaps you do need to adjust some of the variables.

Also what brew temps are you experimenting with? You might just need to try pulling the shot at a higher temp.. 202-203F. Sometimes even higher. The weird thing with the lightly roasted Ethiopian SOs is that sometimes they like lower temps, around 198F. Experiment with both extremes and see how they taste...