So I have been able to try my hand on the temp strip with 60-90C range. A big thanks to you, you know who you are.

One thing that I've really noticed with the temp strips, is that there is a temperature differential(about 5C difference) between different part of the grouphead. That is confirmed (unless there is variation in the strip) and should probably be considered as one of the variable in the future study. One thing that bothered me though, I thought brass(of the group head) is supposed to be a good heat conductor and that the heat should be dispersed pretty evenly throughout the grouphead quick enough?



So, in my opinion, if you place the temp strip properly, you could still get the desired group head temperature with OE's. Calibrate it to your experience. From my temp strip placement above, if I get the grouphead to about 175, sometimes it might seem on the cold side. I would normally prefer it a little higher. For reference, I run mine boiler 0.7/0.9 and pull the lever only when at the bottom of the cycle by bleeding the steam.

I will do more testings and contribute my experience here. But it's really hard to see the color and determine the exact temperature range though. More like winging it but with more visual guidance.

tekomino wrote:Doug, its great you are looking into this.

I would not worry about this since it is easy to warm up group with half pumps and by letting just little water out for lubrication.

+1 You don't in fact actually need to let any water at all, just pump the lever to circulate boiler water above the piston.

Thanks for this very educational thread. I've hooked up my Cremina to a thermocouple but am curious about something Eric mentioned earlier--

erics wrote:edit - high temperature 3M hook & loop is ~ 2 weeks away.

Any updates?

My Cremina looks similar to Sam's, only my strips are reversed, with the 60 - 90C strip sitting right on top of the 90 - 120C.

If I'm honest, I find the strips useless for the first shot. My routine is so predictable that with my eyes closed I can get the exact same results every time. For the second shot on I used to just let my machine sit with the power off for about 5 minutes before pulling again. The 60 - 90C strip should help in this department, so I need to get used to how it reacts versus trying to go off a particular temp indicator.

Anyone out there need 60 - 90C strips? I have 8 extras.

peacecup wrote:Isn't this the problem with all pressurized home levers? At least that's always been my understanding. As long as one only wants to make 2-3 shots at a time, no problem.

Hi Jack,

As you asked me to demonstrate, La Pavoni Millennium Owners, Are Temperature Problems Solved? temperature regulation beyond three shots isn't a problem on the Millennium Pavoni. I'm not exactly sure what their engineers did to fix the temperature issue on that machine and there's no arguing that the build quality isn't up to their prior models and certainly not up to a Cremina.

uscfroadie wrote:Anyone out there need 60 - 90C strips? I have 8 extras.

All of these have been spoken for now. I greatly underestimated the demand, so they went quick!

As you asked me to demonstrate, La Pavoni Millennium Owners, Are Temperature Problems Solved? temperature regulation beyond three shots isn't a problem on the Millennium Pavoni. I'm not exactly sure what their engineers did to fix the temperature issue on that machine and there's no arguing that the build quality isn't up to their prior models and certainly not up to a Cremina.

We're after a little finer-precision on this one - overheat yes/no is ok for making drinkable espresso with minimum effort. The "temperature issue" addressed in this thread is precise replication of brew temperature - something that will require accurate measurements and a lot of trial and error. This is because of the problem inherent in all pressurized lever machines, i.e. boiler temperature is way to high for brewing espresso. In regards to precise brew temp. control, the difficulty lies in the fact that after a shot is pulled the group will be at its hottest temp. Afterwards it will slowly cool back down to "idle" temp. If one can find a group temperature (and related boiler temp) that they prefer for a particular coffee, dose, etc. it should be possible to replicate results. But it will require simultaneously hitting two moving targets (boiler and group temp).

I personally find lever espresso so superior to pump espresso, and so forgiving in terms of a few degrees of temperature, that I don't fuss over this issue.

PC

Jack,

You raise a good point that the study I did was not (nearly, my word) as precise as this one. I've ordered the OE temperature strip and Merle is kindly sending me a 60 - 90 temperature strip, which I'll use to give readouts of group temperature on that machine. It won't be with a thermocouple but will show stability. I'll also measure the coasting pressure with the steam wand pressure gauge from OE.

Given my experience with that machine, though, I'll have to respectfully disagree that the Millennium Pavoni can only be controlled for "drinkable" espresso. The point is not to hype my study or machine in particular but to share experience with a machine you may not have tried. As others have written, with lever espresso machines, cool, warm and hot seem to be sufficient temperature variables for a wide variety of coffees and roasts. This has been my experience with that machine, to my surprise and delight. It is in great contrast to operating a pre-Millennium, dual-switch Pavoni, which is very different and fits your generalization about home lever espresso machines. I also like the pre-M but it has wide and shifting temperature variation that can only be controlled with much more involved technique. I will also study that and then post.

Anyone with a Millennium Pavoni and a stock portafilter for sufficient mass to cool the machine can check for themselves. Chris Moritz (yakster) saw me demonstrate my machine, which is nothing special, just a Millennium Pavoni that has the PSTAT properly adjusted (again, I'll provide a pressure gauge read-out soon) and can be reliably cooled when coasting at full temperature by dipping the portafilter in cool water so it either feels cool, warm or hot to the touch.

Dennis has done a very nice study here. Chris Moritz (yakster) and I plan to do a temperature study for the Millennium Pavoni like the one done here using a thermocouple in a basket and possibly a data logger and software. We won't have free time to do that until early February, maybe. I'll post temp strip measurements much earlier, and these will both be in separate threads from this one.

I don't feel ownership of such a project, though. If someone wants to do it sooner, please go for it!