You're right and I'll correct it. I was referring to releasing steam and very hot water to bring boiler water back to temperature, which is best done through the steam wand.

I just have to re-emphasize the already mentioned importance of knowing your grouphead temperature. This is far and a way the most important factor, at least for the cremina. Anyone with a home lever should read these threads Olympia Cremina Temperature Study, Part 1 , Olympia Cremina Temperature Study, Part 2.

In my Cremina experience, the importance of the p-stat setting was vastly outweighed by the grouphead temp. You DON'T know the grouphead temp without a thermometer or strip on it. You can only guess by touching, and trust me, you can be way off.

You could always add a PID or temperature controller. I put a controller on my old Gaggia lever. I could power it on and leave it in a 'standby' state, say 150F all day then when I wanted a shot just bump the temp up to get the positive boiler pressure for brewing and pull a shot. Then I could bump it up more for steam then turn it back down for standby mode. We discussed it at length on this thread.

Has anyone ever PID'd a lever machine?

i have the hi/low range temp strips from orphan espresso.
i find they are difficult to read/use

where can i buy a digital temp apparatus?

There are many types of digital temperature devices that can be used, even oven thermometers.

I suspect just where to measure temperatures to provide the best information depends on the group design. The steam heated groups such as the 1974-2000 La Pavoni have a particular problem here, because the top of the group quickly after bleeding reaches the boiler temperature, but the area below the piston is what is important, and it is difficult to measure inside--the really important place! The "hot water heated groups" are very different, and I suspect one can get more reliable measurements from them but still with difficulty. There are other systems too, and obviously there are measurement problems with all.

The important thing is the "first cup". Especially with steam heated groups, I am not convinced that the sensible thing to do is simply to bleed the group by raising the handle and then to put the portafilter without the basket on the machine and insert the tip of a probe type oven thermometer into the portafilter spout and watch its temperature rise. When the temperature rises to about 60-5 degrees remove the probe, put in the loaded filter basket and pull the shot. Watch the espresso carefully during the shot and if there be any sign of boiling, cool it with a ramiken of water before making the next one. Other machines might require other temperatures than 60 to 65, of course. Ambient temperature will also require changes.

The idea of inserting the temperature probe into the portafilter is an interesting one. I may try that when my thermometer arrives.

I am starting to think that the most reliable way to get consistent results, temperature wise, is not to bleed the group with water/steam but to let the whole group come up to some predetermined temperature and then pull the shot. I have been using a temp strip and have been putting a few drops of water through the group when the temp strip reaches 60c just to heat everything up. If I am not careful to bleed just a tiny amount of water I overshoot 70c and start to light the 80c "box".

My next experiment is to fasten a digital temperature probe to the back of the group and just watch it come up to temperature as a whole. I plan to use an outside group temp of 70c as my starting place to pull a shot. I'll see where this take me:) So many variables,..

Vc wrote:i have the hi/low range temp strips from orphan espresso.
i find they are difficult to read/use

You got that right. Mine works but I need really good lighting, and watch it carefully as I heat the grouphead with little flushes. And I've had to replace the low temp strip once because with age it became useless.

Vc wrote:where can i buy a digital temp apparatus?

.
Read through this other thread of Gary's: Adding Thermometry to a La Pavoni Europiccola - is long but covers some options for building your own from readily available inexpensive polder or taylor digital probe thermometers, as well as just using a high quality unmodified thermapen ($80 bucks or so.)

FWIW I'm restoring a vintage commercial lever machine and am very new at restoring. I tend to overthink each step before I try it. No harm in thinking. But getting useful digital thermometer readings to fine-tune home lever shots is very easy. If you place the tip of a probe on the lower part of the outside of the group you'll get readings that are so useful you'll reliably dial in your shots for different coffees much better than using those temperature strips. Those readings won't give you the exact temperature in the coffee cake but they'll correlate closely enough.

thanks pat

[anonymized]:

Nice measurements. To compare with standard espresso brewing temps, have you considered sacrificing a basket and making a poor man's Scace (thermocouple inserted through a hole in the basket into the coffee cake) to measure actual brew during a pull?