I moved this discussion here from Bleeding pressurestat lever machines. (Especially 2nd gen La Pavonis)
Didn't want that thread to go too off topic.

EddyQ wrote:Thanks DanoM. I have read this thread, but I guess I need to read it again. And I know I missed your very cool modification!
Pull after pull with no increase of temp . My millennium certainly does not do that. I'm curious what is the temperature you are measuring with your thermocouple? My meat thermometer (certainly not as good as a thermocouple) quickly reaches almost 100C after my first pull. I pull with a reading of 90-94C and pre-warm the group with a few flushes into my cup. I'll have to try cooling my portafilter to see how much heat gets removed between shots. Maybe I could pull shot after shot with that change of technique.

With my mod I'm typically starting pulls between 92.0-93.0c, measured on the front of the group just above the flange, insulated by velcro from ambient air. At the end of pulls I see a rise of temp to the 97-99c range.
Pull shot, steam some milk, pour milk, knock out the puck, rinse the PF & basket, place the PF back into the group, wipe down the basket, grind the next shot.
At that point I grab the basket while checking the group temp and if required dunk the PF 4 seconds into cool water then return to the group. Sometimes I'm nearly at the right temp and will remove the PF, or usually it just stays in without any additional cooling. Just depends on how hot it's running at that moment.
Load the basket, tamp, recheck temp for my exact start temp, load, lock & repeat.

Depending on the beans & roast I dial in the temp and pre-infusion time. Typically shoot for 25 second pulls. Temps are dialed in to the 0.1c range. I think the biggest drawback of this mod is several pumps are required to heat the group, but for the temp stability and repeatability it fits my needs!
Moving into our own place next month, so I'm guessing the La Pavoni will finally get some rest time soon and the Strega can take over!

Wow. Those temps seem to correlate really nicely with my measurements.


I'm going to try this procedure once I overcome my current Pstat issue. I'd like to have a solid method of making shot after shot. Not that I do that often. But when friends are visiting they tend to loose excitement when they have to wait while I frantically try to cool the group. I'll post back here my findings. I'm sure other millennium folks would like the info.

EddyQ wrote:I'm going to try this procedure once I overcome my current Pstat issue. I'd like to have a solid method of making shot after shot. Not that I do that often. But when friends are visiting they tend to loose excitement when they have to wait while I frantically try to cool the group. I'll post back here my findings. I'm sure other millennium folks would like the info.

My guess is you'll find that the millenium group can do a very good job once you 'become one with the pavoni'! Wish I had one myself, but the current mod makes my machine act as close to a millenium group as you can get. Hopefully your friends can learn about patience and the art of small scale home espresso!

You are quite correct DanoM. I pulled a nice shot this morning with my usual routine of heating the group. My group thermometer measured 92C when I pre-infused and pulled. Afterwards, I removed the portafilter and rinsed under cold water. This water was not ice water, but simply straight out of the sink faucet. I put the cooled portafilter back on the group and after a minute or so my thermometer had fallen to 90C! So, this proves I could pull another shot right after the first! Thanks for this tip.
Now, I need to determine the real number of shots before getting dangerously low water in the boiler. But that should be in another thread . . .

EddyQ wrote:Now, I need to determine the real number of shots before getting dangerously low water in the boiler. But that should be in another thread . . .

Regarding the maximum number of shots in a 'tank' I've found that if I slightly overfill my Professional I can get 10 shots without getting below the sight glass. Since you have the Europiccola I would assume you can do the same and get up to 5 shots without getting dangerous.

The La Pavoni rating for these boilers is 8 & 16 shots, but those are split from a single pull. That means about 1/2 oz per split shot! Pretty tiny shot if you ask me.

One last note, I find shots to be a little better and uniform if I overheat the group before the first shot, then cool it down to my target shot temp. All the brass has been heated up to a uniform temperature that way.
Glad you found the information here valuable! That Millenium should be a nice little machine.

I've been using this modification for the last week or so on my 1978 Europiccola, to which I've added a pressure gauge and a group thermometer (measuring above the bell at the 3 o'clock position). Experimentation tells me that most coffees perform well if insert the portafilter/coffee with my measured group temperature somewhere between 197-199F.

Between my wife and I, the machine is used for ~6 shots per day, most of which include milk steaming. Before the modification, this often pushed the group temp above 210F. Even when I'd turn the elements off while not actively using the machine, pulling more than one shot was a constant struggle to cool the group and perfectly time the next shot before the group overheated again (per the thermometer).

After the modification, the temperature of the group is very stable. Even when steaming milk, the group is rarely above 203F, and despite the fact that my boiler pressure is around 1 bar, the temp will actually drop into my target range of 197-199F while I prep the next shot. If not, inserting a slightly cooled portafilter (to drop the temp) or a short pump of the lever (to raise it) easily brings it back to 198F.

Thanks for posting this idea, DanoM, it's made my La Pavoni a joy to use!

Nick

I found this ramekin method from member Rpavlis to work with multiple shots on the 2nd gen LPE. Tips for Controlling Brew Temperature on a Home Lever Espresso Machine

Also end a lever machine session by drawing water into the group from a ramekin to rinse out the bottom of the group to minimize stale deposits on it the next time. Move the handle up and down a couple of times with the ramekin up contacting the base of the group. This gets a lot of the coffee residues out of the system that can create bad flavours.

redbone wrote:I found this ramekin method from member Rpavlis to work with multiple shots on the 2nd gen LPE. Tips for Controlling Brew Temperature on a Home Lever Espresso Machine

Yes, that and other cooling methods are well-known. But this innovation makes the performance of the La Pavoni 2nd gen group comparable to an Olympia Express Cremina. If I come across a 2nd gen machine in the future I will do this mod.

NickD wrote:I've been using this modification for the last week or so on my 1978 Europiccola, to which I've added a pressure gauge and a group thermometer (measuring above the bell at the 3 o'clock position). Experimentation tells me that most coffees perform well if insert the portafilter/coffee with my measured group temperature somewhere between 197-199F.

Between my wife and I, the machine is used for ~6 shots per day, most of which include milk steaming. Before the modification, this often pushed the group temp above 210F. Even when I'd turn the elements off while not actively using the machine, pulling more than one shot was a constant struggle to cool the group and perfectly time the next shot before the group overheated again (per the thermometer).

After the modification, the temperature of the group is very stable. Even when steaming milk, the group is rarely above 203F, and despite the fact that my boiler pressure is around 1 bar, the temp will actually drop into my target range of 197-199F while I prep the next shot. If not, inserting a slightly cooled portafilter (to drop the temp) or a short pump of the lever (to raise it) easily brings it back to 198F.

Thanks for posting this idea, DanoM, it's made my La Pavoni a joy to use!

Nick

Glad it's working for you! I actually run my La Pavoni at about 1.2BAR for steam pressure, and still didn't have overheating issues. Just a non-hot naked PF is enough to bring the temps down to where I need them. And those mini pumps of the lever to cycle a little hot water to the group really help to raise it minimally.

When pulling back to back shots, up to 8 at a time, it's really nice not having to use a ramekin or other cooling, although that does work okay. I tried all the other methods, but this is by far my favorite.

Can this mod be completed without removing the heating element. Can it be done by just removing the group head from the boiler. Would that provide enough access ? Can't say why but I found my current 2nd gen 76 dramatically more temp stable than a previous early-mid 80's brass\copper 2nd gen.