Hi folks,

I recently added a pressure gauge to my two-switch Europiccola pre-millenim. For those of you that may have added this mod, I'm curious at what pressures you find your best shots pull?

When my machine is fully heated up on "II" it tops out at about .9 bar with lots of steam coming out of the pressure relief valve. Idling on "I" it sits at about .7 bar gently whistling -- which I think it a little too hot for brewing.

I've been having pretty good success shutting it down and pulling shots between .5 and .6 bar.

Again, I'm wondering how this compares to others' experience.

Thanks!

Brian,

I had two of the Gaggia Factories (La Pavoni Pros) and found the pressure to be pretty much spot-on with what you are seeing. .7 bar was good for initial shots after a warming flush; however, if pulling a second shot I would turn the machine off so as to help not overheat the grouphead. For milk drinks, I'd shut off the machine within a few seconds of starting the frothing to help lower internal pressure; once again to help to try to not overheat the grouphead more than it already was. FWIW - I adjusted both machines to sit at .7 bar.

I have a newer Millennium model with the pressurestat and added a pressure gauge and recently tweaked with the pressurestat because it was cycling the element on at .5 bar and off at .7 bar and that seemed too cool to me. Now it's cycling on at .6 and off at .85 and I've been a lot happier with the quality of the shots. I wonder how much our ambient air temp in our kitchens, barometric pressure, and altitude are effecting our preferences? Or if there is a little skew in some of the gauges? In trying to break down as many steps as possible with these machines it seems that being able to recognize an over extracted too hot shot versus a cool shot is the only way to set the machine to the proper temp. My shots are still a little blond even with the higher temp. but I think that has more to do with the grind, tamp, and pull than the temp.

When the machine was set at the cooler temps I felt like the shots with less water in the boiler were better. Now I like the shots with the boiler more or less full. I guess I should try one with less water and see if it seems hotter.

Interesting thought about elevation, etc.

FWIW, I live at about 4,500 feet above sea level with ambient humidity typically in the 10-20% range. So, yes, my my machine will probably perform differently under these conditions than if it were in Houston.

if you have a few minutes plug "Scace Thermofilter" into the search engine

this is a custom made portafilter with a thermocoupler to measure the temp of the water in the puck and the Scace II actually has a pressure gauge at the group head

although they're quite expensive from Espresso Parts (around $500) not to mention out of stock

formerly an h-b member had one for rent (with a deposit, etc.) although I don't think it was the 51 mm La Pavoni that would fit our machines

this is the direction I'm going if feasible so that I can dial my pressurestat to give me exactly the temp I want at the puck at my location with my specific machine - there are so many factors like altitude (scaling, leaks, etc.) that it's tough to compare apples to apples

there was a great thread with a title like, "what are we really measuring with boiler pressure?" or something along those lines although I can't find it at the moment

maybe we can convince a LMWDP member to purchase the Scace II when it's back in stock (or make their own) for us to rent in the future - doubt it would be lucrative, but it could off set some of the costs and whomever buys it would obviously be the first to use it

btw - when I first cracked my pressurestat a few weeks ago Stefano who is a well reputed espresso machine mechanic in central Oregon stated that he usually sets an EP between .7 and .9 bar and finds that to be to the satisfaction of his customer base

From what I learned and understand of physics, the altitude and humidity will not effect the boiling point (read: water temperature) in a Europiccola or Millenium.
The steam vessel can be regarded as a closed vessel that is heated, and the pressure relief valve is calibrated against absolute pressure in the vessel via the spring and ball. The ambient pressure on the spring side of the ball will not have much effect on the total.
Same goes for humidity, no effect on the internal pressure and temperature of the water.

Having said that, I do believe that both ambient pressure and humidity can have effect on both grind quality and perhaps even taste perception (and things like evaporation once the liquid is in the cup), thus effecting espresso in the way we experience it. I can even imagine the perception will differ between people living at that altitude (accustomed to it) and those just visiting.

This is just theoretical from my point, I live below sea level......