the PID on the leva is for the boiler, but how does that translate to the water temp at the group head (GH)? well today amazon delivered the thermocouple meter so i decided to test it out.

thermocouple inserted into the PF from the spout. made sure the thermocouple is deep inside where it's near the center of the basket. left the PF on the group head and turned on the Leva for an hour with PID set at 248F. remove PF, pull to flush, then put on PF and pull lever down all the way in pre-infusion stage and let the water run. temp got around 212-213F, so about a 35F gap between boiler to the GH.

since most recommend espresso taste best for medium roast to be around 195-205F, i adjusted the PID to 235, which should give me a temp of 200F range at the GH. followed the same as above... left it on for 1hr, pull a flush, reinstall the PF, and pull lever down all the way. sure enough, the water temp was around 200-203F.

will try out the actual shot tomorrow and see. may have to adjust the grind setting since now at 235F, maybe the pressure isn't that high so extraction time might be off. anyways... interesting to find how water temp change from boiler to the GH. guess the LSM is a big heatsink after all.

That pid is mostly show.
It makes regulating boiler temperature a little bit easier .Instead of taking the lid off to regulate the boiler pressure
with the pid you can push a little button.
The huge brass mass of that lever group is the factor that controls the temperature of the shot.
The micro adjustments of the PID won't make much difference in comparison to the bigger on off cycle of a pressostat.

silkypull wrote: thermocouple inserted into the PF from the spout. made sure the thermocouple is deep inside where it's near the center of the basket. left the PF on the group head and turned on the Leva for an hour with PID set at 248F. remove PF, pull to flush, then put on PF and pull lever down all the way in pre-infusion stage and let the water run. temp got around 212-213F, so about a 35F gap between boiler to the GH..

That's not going to give you accurate temp measurements. You need to mimic an actual shot, not just run water through the basket. Flushing prior to testing will just drive up the group head temp. Run some tests with no flushing after the machine has been on idling for several hours. This will give you your base line idle peak temp so you know how much flushing, if any, is required to hit the shot temp you want for the coffee you are using.

Did you do a boiling water/steam calibration with the new temp meter & tc prior to testing to see how accurate the readings are?

JohnB. wrote: That's not going to give you accurate temp measurements. You need to mimic an actual shot, not just run water through the basket. Flushing prior to testing will just drive up the group head temp. Run some tests with no flushing after the machine has been on idling for several hours. This will give you your base line idle peak temp so you know how much flushing, if any, is required to hit the shot temp you want for the coffee you are using.

Did you do a boiling water/steam calibration with the new temp meter & tc prior to testing to see how accurate the readings are?

the one i got not sure if possible to do calibration or not. how would i go about in testing it? just use the boiling water from the leva? i'll test and play around some more with a loaded shot.

Even if you can't enter an offset a boiling water calibration will tell you how far off it is, if it is off. Use this page to figure out the boiling temp of water at your location: http://microguard.dk/bookmark/icons/water.htm Boil water in a pot & measure the temp with your TC/meter.

Since you don't have a Scace your best bet is to bury the tc in an actual puck. Grind fine enough so that there is no flow out of the puck until you lift the lever. You want to measure the shot temp after the machine is fully warmed up; 1.5 hours minimum,. You are measuring the idle temp so no flushing. Wait at least 30-60 minutes between each test.

What is prompting all the temperature testing? Are you just curious or having issues dialing in your coffee?

i was just curious. i like the taste of the espresso at 248F (1bar), so trying to see if different temp set at boiler and temp at the GH changes the taste much when dose is consistent at 19g.

silkypull wrote:i was just curious. i like the taste of the espresso at 248F (1bar), so trying to see if different temp set at boiler and temp at the GH changes the taste much when dose is consistent at 19g.

Let us know how the investigations turn out. I'm also curious about your experience the first time you decide to take the group apart for cleaning and lubrication. I've read that it's easy but may be challenging the very first time.

JohnB. wrote:Ideally you'd want to determine what boiler temp/pressure will give you the lowest shot temp you'd want to use right off idle with no flush. Once you've got that set you won't be touching the PID for years which is why it's a waste on a machine like this. From there you do some testing to see what difference each second of a flush makes to your shot temp. Once you know what shot temp you get off idle (say 198*F) & how much a 1 or 2 second flush raises that shot temp you can quickly & easily select whatever shot temp you want from idle (198*F?) on up. Saves lots of guess work & coffee in the future.

thanks john. yea i figure as much. once i know what temp and what taste i like for light, medium or dark, i don't think i'll be changing the temp much.

drH wrote:Let us know how the investigations turn out. I'm also curious about your experience the first time you decide to take the group apart for cleaning and lubrication. I've read that it's easy but may be challenging the very first time.

about the cleaning part, yea i'm a bit intimidated by it. i'm pretty handy as i do work on cars and stuff, but since never really see this done before on a youtube vid, I'm not 100%. i figure with machine off and cold, remove the top 4 nuts with hex wrench on bottom, pull lever down and lift up and it'll pull itself out of the GH?

the closest i found on youtube, although not for the alex leva is this: http://www.youtube.com/watch?v=MbHiIr3GCMs

so not sure if it's correct way.