Vintage La Pavoni Europiccola temperature surfing issues?

#1: Post by **RonnyG** » March 27th, 2016, 5:32 pm

Hi all,

I have been trying to find specifics in regards to temp surfing a vintage pavoni ECP and what I have read so far does not match the results I have been getting so I must be missing something. I have a 70-73 version 1.6 ECP with the Massimo/Minnimo switch on it. The group is not a bolt on style as it screws directly into the boiler making the addition of a Nylon gasket (for temp stability) impossible. I use temp strips on the group and aim to start my pull with the strip lit up at 85C/185F. If I try any hotter than this I get tastes of burnt and over extracted shots. When I am done pulling the shot my temp strip is lit up at 100C/212F. I have to go through a couple minutes of cooling procedures to get the group ready for the next shot. I have tried immersing the group with cold water in a ramekin, tried pulling the cold water up into the group with the lever (this seems to make it hotter) cold wash cloth, cold portafilter etc but it all takes awhile to get the group ready. I read of people being able to get the temp ready for consecutive pulls much more easily and quickly. What am I missing? Is a near 30d increase in the group normal for these machines. I have pulled some great shots with this machine but am struggling to stay consistent. I usually use the massimo to initially heat the boiler and when I am steaming but keep it on the minnimo switch for pulling shots. Thanks everyone!

#2: Post by **rpavlis** » March 27th, 2016, 6:38 pm

I have an earlier model-1963-1964 vintage. I never have any temperature problems with it. It is impossible to put a pressure gauge on the sight gauge on mine, so I read pressure by attaching a gauge to the steam tip. It seems to be very consistent at about 0.7 to 0.8 bar. One should turn both elements on to get it up to temperature and then turn off the high wattage element, as you describe doing. I do not like the temperature strips, my preferred temperature device is one of the amazingly inexpensive infra red thermometers. (They formerly cost over US$1000, and now go for about US$10. You need to put a piece of tape on the spots you want to read that have metallic surfaces.) With a bottomless portafilter you can also profile the temperature of the espresso as it exits the portafilter basket with one of these. (I like it to go to about 93 or so by the end of the shot. Others may like it a bit lower or higher.)

Very little group heating with this design comes from thermal conductivity from the boiler. Instead the heating is brought about by bringing hot water into the space between the brass sleeve and the group walls. If you pump the handle up and down you bring in hot boiler water from the reservoir, so the more you pump the handle up and down the hotter the group becomes. I never move the handle after the first shot except to make a shot to avoid overheating. Without hot water coming in heat loss to the air seems to about match any that might be conducted in from the reservoir.

Are you sure that the boiler is not drastically overheated? It should be no more than 120C, and preferably more like 115C.

#3: Post by **drgary** » March 27th, 2016, 7:07 pm

One thing that can build boiler water heat is if the pressure relief valve spring has too much tension. If it's venting normally there shouldn't be much build-up.

#4: Post by **zubinpatrick** » March 28th, 2016, 2:55 am

Don't be afraid to turn it off....keeping it in the min position can still keep it too hot. I tended to get it up to temp, then turn off, then occasionally tuen it on min to keep heat up as required. As others noted the pressure re;lief valve can be very inaccurate as a primary source of temp. I used to tune mine by modding the spring tension/throw but many think that is crazy! so I won't suggest that. Also darker roasts are a lot more sensitive to having that burnt taste, so maybe something a little lighter?

#5: Post by **jonr** » March 28th, 2016, 9:18 pm

I turn it on, pull when the group reaches 76C (this varies with where you measure and the exact boiler temp) and then turn the machine off until the group falls well below 76C. I don't think I could get an acceptable second shot soon after the first.

#6: Post by **drgary** » March 28th, 2016, 10:19 pm

I get acceptable second shots but am using the original spring and ball with light roasts. I shimmed the weakened spring. That's done at your own risk. I tested with steam wand manometer to not let it build too much pressure and removed one of the shims I'd inserted. Because of constant venting these machines aren't meant to run continuously, so toggling off is good too. My technique is practiced enough I'm not measuring temperature. Doing so will help you get to know your machine.

March 29th, 2016, 5:50 pm

Roger, thanks for the replies, by turning the machine off between shots I am having an easier time now with the temp surfing for shots 2 and 3. Thanks again. Are there any levers out there that are super temp stable where you can just walk up and pull after it has fully warmed up?

#8: Post by **drgary** » March 29th, 2016, 6:21 pm

Elektra Microcasa a Leva with heat break gasket (be sure to install longer bolts to make up the thickness) and light enough roast.

Your machine with light roasts or reduced tension on the OPV spring, but you can't keep it running all the time.

A machine with a commercial lever group is much better, there's some temp variation. But the real skill to learn is to spend time with any machine, learn how it responds to using it and adjust for that. I hardly ever burn shots on a La Pavoni or Cremina or MCAL, or my Conti Prestina, etc. because of user experience. Group thermometry really helps as you're coming up that learning curve.

Keep in mind that a home lever is made to heat up quickly, pull a few shots, and that's it for your session. For me one of the advantages of a home lever is its ability to quickly change temperature in response to user control.

#9: Post by **jonr** » March 29th, 2016, 9:01 pm

In theory, one could adjust the boiler temp on a Europiccola down until everything stabilized at temperatures that would produce the right water temp during extraction. Ie, you could walk up and pull even after idling for an hour. Of course the balance would change if room temperature changed and it would negatively effect steaming.

A really smart controller could lower boiler temp as the group heated up - always being ready to provide the right extraction temperature. And have a button to switch to a higher temp steaming mode.