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La Pavoni Europicolla pre millenium pimp strip heatup

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Sooooo - for the Pav heads out there an evolution of the Europiccola was the introduction of the Teflon piston around 1995 - replacing the brass piston , the idea was to prevent or lessen overheating and thus make the pav a more sensitive soul than in its heady youth in the 60's. well that's the theory, fellow member Christos has the sameish year of pre millennium euro and in his rebuild opted for the traditional brass piston, so in a typically coffee forum uk way we have the chance to compare group head temp rise as we have both fitted the same pressure gauge and temp strips to our machines. Is the info below of any use? ive no idea, is it scientific mehh not really but we are having a go to compare Teflon vs Brass pistons in a 1995 euro.

 

the first test was based on the following test conditions

 

Teflon (plastic piston)

machine at room temp

 

boiler filled to top of sight glass

 

water at room temp

 

Portafilter fitted but no basket

 

false pressure bled at 6 min

 

 

The temp rise went thus -

 

7.30 min 70 deg C

9.00 min 75 deg C

10.00 min 80 deg C

12.00 min 85 deg C

14.00 min 90 deg C

16.00 min 90 deg C

 

and that was the max - Chistos over to you for the brass piston test (once your Pressure gauge is fitted) we shall see! which one will win in a fight plastic or brass or who cares anyways !:act-up:

 

[ATTACH=CONFIG]27995[/ATTACH] [ATTACH=CONFIG]27996[/ATTACH] [ATTACH=CONFIG]27998[/ATTACH]

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all opinions are my own I have not received any free equipment or favours from suppliers 

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Sooooo - for the Pav heads out there an evolution of the Europiccola was the introduction of the Teflon piston around 1995 - replacing the brass piston , the idea was to prevent or lessen overheating and thus make the pav a more sensitive soul than in its heady youth in the 60's. well that's the theory, fellow member Christos has the sameish year of pre millennium euro and in his rebuild opted for the traditional brass piston, so in a typically coffee forum uk way we have the chance to compare group head temp rise as we have both fitted the same pressure gauge and temp strips to our machines. Is the info below of any use? ive no idea, is it scientific mehh not really but we are having a go to compare Teflon vs Brass pistons in a 1995 euro.

 

the first test was based on the following test conditions

 

Teflon (plastic piston)

machine at room temp

 

boiler filled to top of sight glass

 

water at room temp

 

Portafilter fitted but no basket

 

false pressure bled at 6 min

 

 

The temp rise went thus -

 

7.30 min 70 deg C

9.00 min 75 deg C

10.00 min 80 deg C

12.00 min 85 deg C

14.00 min 90 deg C

16.00 min 90 deg C

 

and that was the max - Chistos over to you for the brass piston test (once your Pressure gauge is fitted) we shall see! which one will win in a fight plastic or brass or who cares anyways !:act-up:

 

[ATTACH=CONFIG]27995[/ATTACH] [ATTACH=CONFIG]27996[/ATTACH] [ATTACH=CONFIG]27998[/ATTACH]

Great stuff! In the US till Wednesday so will post my findings in detail upon return hopefully with a shiny new pressure gauge waiting for me!

LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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Ok, so here are my results. Machine from cold start, room temperature water filled to top of sight glass. Portafilter in place without basket:

 

I then installed the gauge to determine if the pressurestat is wrongly set but it gives a text book 0.77-0.9 bar reading. I was really expecting it to be way over.

 

First attempt:

Turn on

5:40

6:00 bleed false pressure through steam wand for 15 sec

6:20 60°C

6:30 95°C

7:00 100°C

9:30 105°C

16:00 105°C

Lift lever slowly without releasing water and open steam valve for 5 sec

115°C

18:00 flush 40ml, 115°C

 

Second attempt without bleeding. Again from cold with RT water to sight glass and portafilter without basket in place.

 

Turn on

5:00

5:50

8:45 60 °C

9:30 65 °C

10:30 70 °C

11:00 75 °C

12:00 80 °C

13:30 85 °C

14:00 90°C(high range strip)

15:00 90°C(low range strip)

16:00 95 °C

Bleed 20sec steam (no drop in pressure so may not be false pressure in mine)

17:30 100°C-> 105 °C

18:00 lift lever gently with steam open

110 °C-115 °C

20:00 flush 140ml water. Drops to 105 °C during flow and shoots up to 115°C once lever is down.

Turn off, no temp change after 5 min.

 

So.. here we have it then. Do I adjust my pstat to 0.6bar max and sacrifice milk streaming and possibly enjoy the correct brew temp? Or do I change to the teflon piston first and see if I can achieve @jimbojohn55 stability at 90°C ?

d7f83222d87cc1bcd63db660ac8b4253.jpg01cceff9e206b76e5992a7d73b1437b8.jpg66f3001efffe585d214b6e1cfadf8eb4.jpg


LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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Oh wow, I think my pressure stat is set too high. I go way over 1 bar but still in the green zone. My group head temp can go up to 105 degrees! I use an IR thermometer to measure temp. I can give you my brass piston readings using the IR thermom if you want.

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I think we need some detailed views here folks - what is the ideal temp for a Pavoni ? my guess is that 95deg ?? I would welcome the views of the wider forum as to ideal brew temps?

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all opinions are my own I have not received any free equipment or favours from suppliers 

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I think we need some detailed views here folks - what is the ideal temp for a Pavoni ? my guess is that 95deg ?? I would welcome the views of the wider forum as to ideal brew temps?
Two more attempts this morning with different method and because I actually wanted a coffee. So my intention was to get it just at the correct temp regardless of pressure etc.

So here it goes:

Fill with RT water.

Turn on but this time with steam wand on to bleed off any false pressure from the start and to avoid getting the uncontrollably fast temp rise by bleeding at 6:00 min.

 

5:00 steam starting to exit wand

Lift lever once to push out trapped air in the top of grouphead and for it to be replaced by steam and leave steam valve on for 15 sec.

At that stage grouphead was barely at 65°C

5:15 grouphead at 90-95°C

As I've now bled both boiler and grouphead I don't expect to see it shoot up that much in the next couple min.

Grind and prep basket

7:15 lift lever

Lock and load, grouphead at 100°C

7:30 pre-infusion for 5-7 sec

Extract 13.5g-> 26g Northstar LSOL

8:00 extraction complete

Temp during extraction was at 90-95°C

Results, tasty not scalding for a change, nice crema, happy!!!

 

Grouphead after extraction went to 110°C

 

Try second shot at 15:00min

15:00 115°C

Prep, lock and load at 15:30

Pre-infuse and pull

Temp 110°C throughout pull!

Exact same dose, yield, tamp

 

Results, world apart. Bloody hot, broken crema, burnt lingering aftertaste. Down the sink.

So. I basically get one chance at 7:00 min with my current setup.

Ramekin cooling has almost no effect once above 110°C. Neither does turning machine off for 5 min. Maybe wet towel+ turning off would work.

I'm therefore left with options of pstat lowering or returning to teflon piston.

 

@jmbojohn55 I can't seem to be able to see your pics from first post. Is the placement of your strips similar to mine?


LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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Oh wow, I think my pressure stat is set too high. I go way over 1 bar but still in the green zone. My group head temp can go up to 105 degrees! I use an IR thermometer to measure temp. I can give you my brass piston readings using the IR thermom if you want.
That would be very helpful! Thank you. Also could you specify model and year of your machine. I know it's in a separate thread but just to have it available on here too!

LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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So. I basically get one chance at 7:00 min with my current setup.

Ramekin cooling has almost no effect once above 110°C. Neither does turning machine off for 5 min. Maybe wet towel+ turning off would work.

I'm therefore left with options of pstat lowering or returning to teflon piston.

 

Christos you should try a mistifer to spray water on the group. I use this in combination with my IR thermometer to get the desired group temp of 90 degrees. I might make a short video showing temp warm up, spraying to cool and some other stuff.

 

Mine is a 1995 pre-millennium

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I get one good shot out of mine and then they rapidly diminish. I have an older Euro so it will have the brass piston. Where do you get the temp strips from, I could use some?

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I get one good shot out of mine and then they rapidly diminish. I have an older Euro so it will have the brass piston. Where do you get the temp strips from, I could use some?
After a fair bit of searching I found these which look identical to orphan espresso ones. Just plug in title on Amazon.

 

For 90-120 range (1 in a pack)

Digitemp 7 Level Horizontal Dual Scale 90°C to 120°C (194°C to 248°C)...

Sold by: Good Life Innovations Ltd (Colour Changing Products)

£1.91

 

And

For the 60-90 range (2 in a pack)

 

Milk Frothing Barista Thermometer - Make perfect froth for your...

Sold by: Good Life Innovations Ltd (Colour Changing Products)

£2.65


LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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@jmbojohn55 I can't seem to be able to see your pics from first post. Is the placement of your strips similar to mine?

 

Same as just lower at the top, doubt 5 mm will make a big difference - but might be wrong!

 

WP_20170719_18_17_48_Pro.jpg

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all opinions are my own I have not received any free equipment or favours from suppliers 

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so digging around the tinterweb and this forum many things are said about optimal temp - at the end of the day taste should always lead the way however this chart was of interest

 

temps.jpg https://www.fivesenses.com.au/blog/brew-temperature-and-its-effects-on-espresso/

 

Quote -

 

(There are a few trends you can see in this graph:

  • The amount of citric acid extracted falls as the temperature increases from 94 to 100°C.
  • The amount of malic acid in the cup is lowest at 94°C.
  • Extraction is optimised at 94°C (sucrose/sugar extraction is at its peak), with a large increase up from 74°C.

Even with this snippet of data, you can see the huge effect brew temperature has on constituent balance*. If this isn’t a great explanation for the taste differences in our cups, then the other route to explore the huge effect on taste which we get from very small differences in extraction yield.)

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all opinions are my own I have not received any free equipment or favours from suppliers 

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After a fair bit of searching I found these which look identical to orphan espresso ones. Just plug in title on Amazon.

 

For 90-120 range (1 in a pack)

Digitemp 7 Level Horizontal Dual Scale 90°C to 120°C (194°C to 248°C)...

Sold by: Good Life Innovations Ltd (Colour Changing Products)

£1.91

 

And

For the 60-90 range (2 in a pack)

 

Milk Frothing Barista Thermometer - Make perfect froth for your...

Sold by: Good Life Innovations Ltd (Colour Changing Products)

£2.65

 

Perfect, thanks I'll order them now

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Pstat lowered to 0.95 bar max down from about 1.1 bar. Group still running hot but first shot definitely seemed cooler with "different" flavours. Might even go done further!

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Same as just lower at the top, doubt 5 mm will make a big difference - but might be wrong!

 

[ATTACH=CONFIG]28181[/ATTACH]

Thanks for that! The only thing I noticed with having then the other way round is that the 90°C of the high range strip (placed above) lights up before the 90°C of the low range strip (placed below). I think you can get at least 5°C higher temp in those 5mm. Once I'm done tinkering with pstat I might swap them around.

LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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UPDATE!

 

Tackling temperature by lowering pstat.

 

So now that I have the gauge installed I can monitor pressure changes in the boiler.

I removed the bottom and adjusted pstat to lower it. I first turned it clockwise (direction to boiler) by half a turn. That had the opposite effect and my safety valve went off at 1.1bar! Oops, I guess it's the other way then.

This time turn anti clockwise (ring moves closer to pstat mechanism)

Half turn had small effect 0.7-0.8 bar cycle.

Extra half turn (full turn total) no effect 0.7-0.8 bar cycle.

Extra 1/16th of turn (min setting) 0.75-0.85 bar :/

 

Fill boiler with RT water and turn on with steam valve open

4:50 pressure build up and steam starts exiting wand. Pull lever up slightly and lower to remove trapped air

5:15 60°C

5:30 75°C

5:45 85°C

6:00 100°C

6:30 105°C

Pressure 0.75-0.85 bar cycle

Espresso at 9:00 115°C

Terrible, scalding, bitter

 

Bummer.. I read somewhere in home barista about disassembling pstat and reversing some pin, not sure I want to risk it. (http://www.spanglefish.com/avicennassolution/index.asp?pageid=243551) and (http://www.home-barista.com/levers/obtaining-lower-settings-in-signal-lux-m3-pressurestat-in-la-pavoni-t40757.html)

 

Anyway so that was my attempt at lowering temp but to no avail.

I tried misting the grouphead as suggested by @fatboyslim but as mine goes up to 115°C there was no amount of spraying that can cool it down and it also leaves too much mineral residue on all the chrome.

 

So my current solution is turn on with steam valve open until steam starts coming out. Lift lever just below water exit level and push down to remove trapped air. Turn machine OFF at 0.5 bar. Prep basket and make coffee. Temp at the head hovering between 90-95°C.

Re heat by turning on to 0.5bar.

Only tried one espresso with that method and it tastes a hell of a lot better than pulling it on the hot side.

 

Any thoughts on the matter?

I will try swapping to teflon piston to see if that allows for normal operation and stable temp but I'm puzzled as to why the pstat doesn't go any lower.

Edited by christos_geo

LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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I think that different pressurestats were tried over the years http://www.francescoceccarelli.eu/La_Pavoni/Faidate/pressostato_eng.htm

 

might be just a case of swopping the microswitch out - poss its got a bit stiff or the contacts inside gummed up - having said that its kicking in at the right pressure so maybe its fine

 

not sure - this might fit http://www.ebay.co.uk/itm/MICROSWITCH-PIN-PLUNGER-SPDT-15A-Part-V7-1C17D8-/272039549727?epid=1440177332&hash=item3f56d21b1f:g:FsoAAOxyiRlSa7-s

 

its the right amps at upto 15A

 

would be interesting to swop to Teflon and see the difference

Edited by jimbojohn55
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all opinions are my own I have not received any free equipment or favours from suppliers 

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This is making me wish I got around to installing a pressure gauge on my LaPav. I installed the brass piston, simply because it was brass and therefore 'better' than plastic...but now I wonder! I always thought my shots were a bit hot but can't do much about it currently.

I remember seeing you post the source for your adapter @jimbojohn55, but can you link it here too for reference?

 

edit:

http://wilycafe.com/page7/page7.html

Edited by timmyjj21

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I think that different pressurestats were tried over the years http://www.francescoceccarelli.eu/La_Pavoni/Faidate/pressostato_eng.htm

 

might be just a case of swopping the microswitch out - poss its got a bit stiff or the contacts inside gummed up - having said that its kicking in at the right pressure so maybe its fine

 

not sure - this might fit http://www.ebay.co.uk/itm/MICROSWITCH-PIN-PLUNGER-SPDT-15A-Part-V7-1C17D8-/272039549727?epid=1440177332&hash=item3f56d21b1f:g:FsoAAOxyiRlSa7-s

 

its the right amps at upto 15A

 

would be interesting to swop to Teflon and see the difference

Thanks for the eBay link. Pstat looks pretty clean and it does seem to be responding to the ring being turned but it just doesn't seem to be wanting to go below 0.7

Anyway, considering 0.7-0.8 is a perfectly reasonable pressure I'll make myself a coffee in the morning at 0.5 bar when I'll hit the off button and then get round to swapping pistons. That will definitely give us some answers.


LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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UPDATE!

 

I tried misting the grouphead as suggested by @fatboyslim but as mine goes up to 115°C there was no amount of spraying that can cool it down and it also leaves too much mineral residue on all the chrome.

 

 

Just for info, first shot this morning. Group at around 90 degrees, lift the lever just for a short blast before attaching PF. Extraction was at around 92-95. After the extraction the group was at 98-99.

About 4 squirts from my mistifier and the group was then at 80 degrees. Seems to work well for me. Powering off between shots is also vital if you want to make more than 2 shots.

 

Subjectively the shot tasted excellent :)

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FURTHER UPDATE!

 

going back to the teflon piston :(

 

As @timmyjj21 said and I also thought, brass is 'better' than plastic.

As much as I'd love to believe that, it simply ain't true in the context of pre-millennium europiccola thermoregulation.

 

Swapped piston back to teflon this morning but only after I had a tasty shot with the brass one. That did involve turning machine off at 0.5 bar to ensure grouphead temp did not exceed 100°C. 13.5g-> 24g LSOL. Good result, fruity sweet bit bright but think that's the beans. However got spongy pull and had to lift lever again to help water enter group due to low pressure.

 

Now Teflon. Don't have accurate temp per minute as machine as already heated up while changing piston (patience is a virtue... if you have it) but!

Let it get to full pressure (0.7-0.8 bar cycle) bled both boiler and grouphead and this time the grouphead creeped up slowly to the 95°C and barely lit up the 100°C mark. This is in contrast to the rapid jump to 115°C with brass after bleeding at full pressure!

Pulled a shot, I think the max reading before pulling shot was 105°C.

13.5g -> 24g same flavour notes, brightness went down a tiny bit but no bitterness coming through. Lever was firm with no sponginess.

 

Success? Too early to tell but I think a 15°C difference is massive. Also a £20 brass piston paperweight is a massive disappointment. If I could lower my pstat it might have been feasible but it won't go lower.

I guess it works in the old pavonis and the post millennium as they have either a brass or plastic sleeve within the group offering some kind of stability and thermo buffering to group temp. @fatboyslim if you had a moment to make a vid of your misting that would be great! @jimbojohn55 I will swap my strips round so we will end up with a virtually identical set up. I do think the higher the strip the hot it will be but as we are interested in the water temp closest to the puck I think you're correct in placing the high range strip lower.

657260658a4f92c261ecd7841570fb86.jpg

Edited by christos_geo

LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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I think there is something about water level and temp - I've noticed a very slow rise to 75 and no further, when the boiler is half empty - early days will keep an eye on this

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@christos_geo as requested. First video literally just shows the cooling, second video shows cooling and then pulling a shot (with soundtrack).

 

Just cooling

 

Cooling and pulling a shot

 

Both are available in 4K :)

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@christos_geo as requested. First video literally just shows the cooling, second video shows cooling and then pulling a shot (with soundtrack).

 

Just cooling

 

Cooling and pulling a shot

 

Both are available in 4K :)

You have it nailed by the looks of it! Thanks for making the video.

Tried different approach this morning where I don't bleed the machine until it's up to full pressure.

Previously I've been leaving steam valve open from startup and only turning off once steam comes through and have lifted lever once. That means that by 7 min in starting to run hot.

Today I let it get to normal operating pressure and as I hadn't bled the group was at 70°C even at 10min. When I was ready to go I bled false pressure through steam wand and lifted lever which brought it to 95°C.

Will be trying that out few more goes and see how I get on with it. If anything it gives me more control as to when i pull the shot as I can just leave the machine un-bled till I decide to pull the shot.

Ordered myself an IR thermometer just to have an extra indicator so will update once I know more !


LR - EK43S; Ceado E37S; Aergrind; Comandante MK3 - Syphon & V60 - patience

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Previously I've been leaving steam valve open from startup and only turning off once steam comes through and have lifted lever once. That means that by 7 min in starting to run hot.

Today I let it get to normal operating pressure and as I hadn't bled the group was at 70°C even at 10min. When I was ready to go I bled false pressure through steam wand and lifted lever which brought it to 95°C.

 

Great info. I have combined not bleeding pressure until ready to extract with only half filling the boiler but in the end I still end up spraying the group with my handy dandy mistifier. I also watched a video showing someone just gently pumping the air out (up and down a short way) with the lever fully extended before starting the pull down.

I think the pre-infusion is an art form in itself! Can't wait to get a naked PF :)

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