How HOT is your pavoni?

[peterr]

hi - i have a la pavoni europiccola, and i wanted to know how hot my espresso was brewing at. i bought a good digital candy thermometer, tested it in boiling water (reads 212F!), and then tested the temperature of the water that came out of the group head. i ran lots of water through, and made sure everything, including the cup i was pouring into was as hot as could be. the highest temperature i could measure was 186 F. is this what the pavoni should brew at? i was expecting something at least 10 degrees hotter. has anyone else done this? does anyone have any official data as to what this machine should brew at? am i measuring wrong some how?

thanks!
peter

[oly_puller]

Hey Peter -
First off... don't panic. I don't have an advice about your particular machine, but I've been going through this same issue with my Olympia Cremina 67 for the last week or so. My post is Olympia Cremina 67 brew temp adjustment.

Anyhow- in all my work to try and figure out *how* to adjust my temp/pressure, I started to realize I might be basing my worry on a bad assumption - that my method for testing brew temp was not so good. So - I've ordered a thermometer from sweetmarias's http://www.sweetmarias.com/prod.roastkits.shtml that has the thermocouple probe - now with this, I'm thinking it can be placed inside the portafilter and then more accurately test the water temp.

Until it arrives though - I'm just sort of going to put it out of my mind and stick to Pete's coffee or something - I'll save the good stuff until the machine is dialed in.

I'm sure you were hoping for an *answer* - but maybe $35 later, you'll be able to move forward and figure out what to do, knowing your method and reason for concern are sound and justified.

Good luck - and I'll post an update on my other thread after I get the thermometer to let everyone know how it works...
Pt

[HB]

the highest temperature i could measure was 186 F. is this what the pavoni should brew at? i was expecting something at least 10 degrees hotter.

Given the method you're using, that sounds about right for an "in the ballpark" temperature. I use the Fluke 54-II and a type-T thermocouple:


Datalogging digital thermometer

It's expensive though (around $300) and can measure directly in the portafilter basket. However, as we discussed extensively towards the end of the Scace Thermofilter Temperature Device thread, even in-basket measurements have shortcomings. Honestly I haven't spent much time temperature profiling lever machines because they're so dynamic, i.e., you can't run test-after-test and see the same result. My approach to learning the Microcasa was to crib notes from experienced owners and then adapt as needed by taste. Chris' La Pavoni Pro in the hands of pros includes step-by-step instructions. Don't be afraid to "waste" a few pounds of beans learning how to operate a lever machine.

[oly_puller]

Hey Dan -
I don't want to high-jack Peter's post, but after reading the link you included about a LaPavoni in the hands of professionals, I'm wondering- do all lever machines have the characteristic of having their temp and pressure tied to one another? If that is the case - then would it be best to just dial in the pressure to 1.2 -1.5 and get the timing down on how hot the machine got?
Interesting stuff... If that's the case - all my questions about my Cremina being too hot are answered by simply getting pressure gauge and getting that dialed. That said... I wonder what pressure one of these should be set to - LaPavoni or Olympia- they'd be about the same, no?
Pt

[HB]

If that is the case - then would it be best to just dial in the pressure to 1.2 -1.5 and get the timing down on how hot the machine got?

I've only worked with three lever machines - Elektra Microcasa a Leva, Olympia Cremina, and briefly with Steve's La Pavoni Europiccola - and they all operated similarly with regards to temperature, i.e., you must pay attention to warmup time as the nature of the beast. Others would have to confirm, but I believe ~1.2 bar is a common setting among them. One of the to-dos on Steve's restoration project is regulating the boiler pressure, which will be extra fun since there's no boiler gauge. We discussed temporarily fitting it with one, probably off of the steam arm assembly. He's still waiting on parts from Switzerland though, and the handles from Les are yet to arrive.

That said, why are you adjusting the boiler pressure at all? Steve's planned adjustment is part of a repair, but normally the factory setting would be fine. I've never seen any need to adjust the setting on the Microcasa either.

[oly_puller]

That said, why are you adjusting the boiler pressure at all? Steve's planned adjustment is part of a repair, but normally the factory setting would be fine. I've never seen any need to adjust the setting on the Microcasa either.

Well, I wouldn't have even thought to fiddle with it - but then I started reading on-line and got ultra paranoid that my machine was too hot since many of my shots don't look anything like the pictures I've seen here at HB or at espressoP0rn.com...

Long before I got my machine, my father had it - he was a tinker-er - and it overheated and had to have the wiring redone- As a result, I suspected he found the boiler pressure control and cranked that puppy up to get an ultra fast steam going for his milk - Anyhow, after reading around here, and being suspicious of my machine's settings, I too started to try and measure the temp out of the boiler at the screen and found it to be about 212 or so degrees!

After that I was on a quest to figure out how to cool it off- so far, it seems that pressure and temp are controlled by the same adjustment - so, as I said- I plan to just set the pressure appropriately and be done with it. From there- I'll just try to keep fresh beans, and perfect my grind, dose, tamp, lever pressure and what ever else there is to this *voodoo* art we call pulling a shot!

Pt

[cannonfodder]

The temp is controlled with a pressurestat, just like the controls for a HX machine. Since pressure is directly related to temp, the boiler pressure will give you a very close guess as to the boiler temp. You get some cooling as the water passes from the boiler to the grouphead.


Boiler pressure (bar) Water temp (Fahrenheit)
1.0 253
1.1 255
1.2 257
1.3 259
From Dan's HX Love Article

Problem with the Pavoni (and my Gaggia) is that the GH is directly attached to the boiler. The longer the machine is on, the hotter the GH will get. Eventually it will overheat and have to rest for an hour to cool down.

The 1.2 boiler pressure sounds high for these types of machines. My Gaggia runs about .9 much over 1 bar and you hit the red on the pressure gauge. There is also a pressure relief valve in the boiler cap. If you turn the pressure up you may blow the valve (think of opening the pressure relief valve on a pressure cooker, WOOSH).

Using the Styrofoam cup with a type K TC in it, I get about 192F after a warm up of about 8 min after it hits temp. Guess about 5 degrees drop as the water passes through the portafilter and drops through the 68F air in my office into the cup puts me at about 197-200F, longer warm up=higher temp.

I just got a couple of OmegaLock fittings. I am thinking about mounting one in the bottom of the boiler under the base and put a TC in it so I can watch the temp. no real reason other than I have the fitting.

[j7on]

The 1.2 boiler pressure sounds high for these types of machines. My Gaggia runs about .9 much over 1 bar and you hit the red on the pressure gauge. There is also a pressure relief valve in the boiler cap.

This might be the biggest difference we had discussing these machines, apparently there are different pressure gauges on different machines(gaggias & pavonis & even pavonis & pavonis)
Some people have wondered about the "high pressure" i drive my pre-mill pavoni(1.2 - 1.3, set at pro shop) but after readind that about "much over 1 bar hits the red zone", well my gauge has the following markings:

0 - 0.75bar - "no pressure zone"
0.75 - 1.5bar - green zone
1.5 - 2.5bar - red zone

I wondered about this when everybody was tellin to go with pressures from like 0.5 - 0.8, even if i take the 0.8 i get a dribbling, stinking "half-a-cup"!

[cannonfodder]

Interesting. I can tell you that my Gaggia Factory, when the pressure gauge is at .5 my boiler temp is 228F, at 1 bar it is 243F. Using a type K thermocouple held in the spout opening, after about 8oz of water it stabilizes at approximately 213F. I assume that the initial water flow is lower than that, but after a continuous flow of water, the grouphead levels off at 213F. Even with my new handy dandy temp controller, my timing has to be just right. It is a bit more forgiving now but still much more sensitive than my E61 machine.

[Jarno]

Curiously then, how hot is the group head for an optimal espresso shot and how hot is the group head when it is "overheated"?

[mogogear]

I am just guessing here, but you are looking for more than "Hot enough" and "Too hot" --right? Ahhhh, the hunt......

[peacecup]

It all about taste (unless its either very cold or very burnt). Try getting the coffee ground and everything ready, then brewing as soon as the machine gets up to pressure, while the group is still cool enough to touch (and therefore sink a lot of heat). If you like it great - if not pull a second shot - this is where most people like their lever machines to operate (I prefer a cooler group personally). Try a third - the group should be getting pretty hot - how's it taste. Then try a fourth - this is where you'll begin to see effects of overheating, unless you are cooling the group.

Take a look on the web - at 1 bar pressure water boils at ~230 F, so the brew water leaves the boiler around that temp and cools as it enters the group. I've got my pressurestat set below 1 bar because I prefer cooler shots.

PC