Hi everyone, I'm new on here but have been a reader for a couple of years.

I've just replaced the pump, upgraded the OPV (to an Izzo one) and serviced the group head of my Expobar Brewtus II.

Anyway, all seems ok but I've noticed that when I push the lever right down to release the pressure after a shot, the pressure remains on the gauge. If I then move the lever back up until just before the pump operates the pressure is released along with some water. I can move it from this position back down again and back and some more water will come out. I'm running it from the tank in case that matters.

I have read something about this but can't remember where and to be honest after doing all this my brain is a bit numb so help and an explanation would be greatly appreciated.

Just to add it may well have been like this before but I've not noticed. You tend to notice these things when you work on the machine.

Oh, and just on the off chance, if anyone lives in the Manchester area in the UK and has a portfilter with a pressure gauge and thermometer fitting and would be willing to help me set it up properly then please let me know. I don't mind some form of payment. It doesn't seem worth buying one.

Thanks

Dan

dan1502 wrote:Anyway, all seems ok but I've noticed that when I push the lever right down to release the pressure after a shot, the pressure remains on the gauge. If I then move the lever back up until just before the pump operates the pressure is released along with some water. I can move it from this position back down again and back and some more water will come out.

Sounds normal, but read Is there a purpose for the E61 middle brew lever position? to convince yourself. The short answer is that until the E61's upper chamber valve opens, the hydraulic system between the pump and brewhead remain pressurized. When you lower the brew lever, only the brew chamber and expansion chamber are depressurized.


E61 in idle position. Please do not copy this copyrighted image

Note that if the hydraulic system prior to the brew chamber were not closed when idle, air bubbles would form in the upper leg of the thermosyphon loop and the grouphead would go cold. This diagram shows why:


From the Buyer's Guide to the Expobar Brewtus

Thanks, it's that article that I have read at some point in the past, I just couldn't remember where I'd read it. I guess it's also possible that prior to the service, the pressure dropped off and that the new springs and gaskets mean it is now held but I couldn't say for sure what was happening before.

Now I just need to set the pressure and temperature properly. I've set the pressure to 10 bar at the gauge when a blind filter is in place. Temperature wise I followed the recommended offset when I first bought it but have since read that the need to adjust can be partly due to the poor original OPV so now I've upgraded I'd really like to check and set it properly.

As long as there's a steady flow, the onboard brew pressure gauge reading on the Brewtus III is close enough. You only need a pressure-sensing portafilter if you have the original Brewtus that was not equipped with an onboard brew pressure gauge.

I was told by a supplier that the gauges aren't very accurate. I did set it to 9 but set it to 10 after reading an article on coffeetime wikidot that said 10 was generally best for these machines. I've not had a chance to make a coffee since doing everything yet (finished too late in the evening - I wouldn't sleep!) but hopefully it will be good. It's just be nice to check everything with the manometer/thermometer the once then leave it at that. I'm a bit of a perfectionist and consider myself a bit obsessed with coffee and machines but do not want to get too into messing about with it all as all I really want is a decent cup of coffee! (Though I can understand how people do get that into it all).

The gauge on my Brewtus behaves this way and its the way it has always been. I have a vibe pump model fed by the water tank.

Ok, thanks. I now just need to set the brew pressure correctly. I set it to 10 bar with a blind filter but my coffee is tasting bitter. I'm guessing I need to reduce it a bit?

Lowering the pressure can't hurt; I recommend 9 bar. But bitterness could also mean the temperature is too high, it's overextracted, worn burrs, etc. See Diagnosis of Extraction Problems for background information.

Thanks, I have read that before but it was a while ago and good to read again. I don't think it's that far off to be honest and may have been worse due to all the new parts having changed the pump, OPV and springs in the grouphead.

The gauge is currently showing a fraction over 9 bar whilst making espresso (not with the blind filter) so I might just knock the pressure down a touch.

I haven't tried timing everything and measuring volume etc for a while so will do so when I get time. I use a dynometric tamper and always use a bottomless portafilter just to try and get consistency and eliminate some variables. I then tend to adjust the grind. Part of the problem is that I tend to buy a selection of coffees so no sooner have I got one just right and it's on to another!

What I would really like is for an expert to come and make great coffee with my machine to give me a benchmark. I've always meant to take a lesson for this reason but my wife thinks I'm nuts! I guess I'm at that stage where I have reasonable technique, understand quite a lot but would benefit from help pulling it all together.