Hi,

 

Has anyone here work with a Brasilia before?  I have a Portofino 2 group and trying to adjust the temperature of the brew.  Thanks

Views: 1202

Reply to This

Replies to This Discussion

The Portofino is an HX, yeah?
Adjusting the pressure stat raises and lowers the pressure that the heating element generates by raising and lowering the temperature of the water in the boiler. The two are inter-linked.
The brew temp is adjusted through flushing the HX. Usually by letting the group run until it stops sputtering/spewing boiling water, but more accurately by checking how long/much it takes to flush the group to the desired temp with an accurate TC and a decent digital thermometer.
I use a Scace Device and a Fluke 54 II that I've modified to test brew pressure as well.
Thanks Chris, sounds like there's not an easy way to control the temperatureChris said:
The Portofino is an HX, yeah?
Adjusting the pressure stat raises and lowers the pressure that the heating element generates by raising and lowering the temperature of the water in the boiler. The two are inter-linked.
The brew temp is adjusted through flushing the HX. Usually by letting the group run until it stops sputtering/spewing boiling water, but more accurately by checking how long/much it takes to flush the group to the desired temp with an accurate TC and a decent digital thermometer.
I use a Scace Device and a Fluke 54 II that I've modified to test brew pressure as well.
Like Chris said, start with the pressurestat setting. That's a good starting point.

Here's a great how-to piece over on Home-Barista on how to finesse hx temps. Commercial gear will not necessarily be quite as sensitive as the home stuff, but this is still a good read. A craftsman will understand the limitations of the tools and know how to work with them to make great things happen.
If you guys don't mind could you point out where the pressurestat might be on the Brasilia. I am very new at this and trying to ask the sales rep on how to adjust the temperature was a non starter. All he said was if your dial is pointing at 1 your are set to go.
To a certain degree, he may be right.
What makes you think that the brew temp is off?
Adjusting a pressure stat isn't difficult, but there are dangerous aspects to it if you're not familiar with what you're doing. Anything from popping your machine to electrocuting yourself to death.
The p-stat is a switch that connects electricity to your heating element, and is driven by the pressure from the boiler. So, looking at the guts, find the boiler, find the heating element (where big wires are connected to the boiler) and follow those back to the next connection in line. That should be the p-stat. Confirm that by finding the boiler connection to the same lil box (via a small copper tube, usually). Somewhere on this contraption should be a fairly well marked adjustment screw. It may be under a cover. A quarter turn at a time (usually 'in' is higher temps, 'out' is lower. What you're actually doing is moving a diaphragm with contacts attached to it closer to, and further away from, the opposite contacts which make the connection to the heating element.
When they close, the element heats the water, creating pressure in the boiler, which pushed the diaphragm, which disconnects the heating element, which allows the water to cool, which reduces the pressure, which allows the diaphragm to relax, which makes the contact, which sends electricity to the heating element , which... well, you get the idea.
The adjustment screw just decides where this entire process starts.
If you're not having a really darned good indication of what your brew temperature is already, however, I'd be hesitant to try to start solving problems that I'm not sure I have. Look for a 0.2 Bar dead-band (the area between where the heater kicks on and kicks off again) between 1.0 and 1.2 Bar. If and when you decide to adjust the p-stat, try to adjust it and watch the gauge. Look for where it goes on, and off, and let it cycle a coupla time before adjusting again. 1.5 Bar is way, way too much pressure for decent coffee.
I just want to echo Chris and Brady. You might not actually have a problem that requires the adjustment of the p-stat. Go through the tutorial Brady linked and get comfortable "temp-surfing" with your machine. I think you'll find that understanding the flush process on your hX machine might solve your issue.

What kind of temp problems are you having, by the way? Too low or too high? Is the machine left on all the time? Do you keep the portafilters in the groups all the time? Is the machine new? Tell us how you are using the machine and we might be able to help figure out the problem.
This post is timely. I just finished refurbishing and modifying a 2gr Portofino. The pressurestat should be at the back-right of the machine, behind the boiler. I found that the groups do tend to run a bit hot, even with appropriate boiler pressure so I installed 2.5mm flow restrictors between the boiler and the group. This took it from about 7 seconds of steam and sputtering to around 2. My machine is at home, though, and not under heavy use. If you're using the machine at high volume, you'll need the temperature to be a bit higher so that you can pull shots constantly and not bottom out your temperature and have to wait to pull the next shot.

All that being said, if you don't know how to temperature surf on a HX machine, you're wasting your time worrying about your starting temperature. Brady's link is a great one. Once you're proficient, you can decide whether or not your current group temp is good for your work flow and start fiddling with the pressurestat and flow restrictors.
Thank you so much for explaining how to look for the pressure stat. I was following one of the tutorial from Schomer to measure the brew temperature. I made 6 shots one after another 1 min apart. and took temperatures at 10s, 18s, 25s. My avg temp is roughly 149, 169, 186 respectively. I took the temperature using a digital fluke with a K-type bead probe. I stuck the bead end into the hole where the espresso is coming out from the spout. That temperature should be fairly close to the one with the sensor integrated into the portafilter. From the numbers above, I am no where near the 195 range... According to Schomer, if it's under 195.. the brew would be under extract w/ a sour taste. Am I going at this correctly?

Mike Sabol said:
I just want to echo Chris and Brady. You might not actually have a problem that requires the adjustment of the p-stat. Go through the tutorial Brady linked and get comfortable "temp-surfing" with your machine. I think you'll find that understanding the flush process on your hX machine might solve your issue.

What kind of temp problems are you having, by the way? Too low or too high? Is the machine left on all the time? Do you keep the portafilters in the groups all the time? Is the machine new? Tell us how you are using the machine and we might be able to help figure out the problem.
Ok, so I recheck the temperature again this time using the foam cup method with a dial poking through it diagonally. No coffee this time just running 2oz of water into the cup and I can get consistently temperature >210F. So I guess I wasn't measuring the temperature correctly the 1st time. I figure the hot liquid running over the thermocouple would be enough to provide temperature accuracy. Anyway, looks like all I need to do now is learn to temperature surf. Thanks guys for all your help.

Reply to Discussion

RSS

Barista Exchange Partners

Barista Exchange Friends

Keep Barista Exchange Free

Are you enjoying Barista Exchange? Is it helping you promote your business and helping you network in this great industry? Donate today to keep it free to all members. Supporters can join the "Supporters Group" with a donation. Thanks!

Clicky Web Analytics

© 2024   Created by Matt Milletto.   Powered by

Badges  |  Report an Issue  |  Terms of Service