Hi,

I have never used an E61 group head. But one of the things that keep echoing on the internet is that it does not have same temp stability as with integrated group head. On a logical level it makes sense (it does lose more heat to external environment than the other). But by how much? I understand it would depend on the exact implementation but on average how much difference can we expect. Like Elizabeth vs Bianca, both from Lelit. I saw a measurement for Bianca, with PID targeting 96°C the Scace reported 94.8°C to 93.7° toward the end of the shot which I believe is great. How much better we can expect with a integrated group head?

Here’s something I’ve learned from a year with the Linea Mina. Reading specs on the internet and saying ‘It must make coffee like this’ is like reading a menu for a Michelin starred restaurant and saying ‘I know exactly how that will taste’.

I think there’s a misconception (and admittedly it’s one I had before the LM) that temp stability refers primarily to a machines ability to keep a stable temp for back to back shots. People say things like ‘temp stability is great if you want to make 5 shots back to back’ etc. But having had a Gaggia Classic, Silvia (a machine not exactly known for its temp stability) a Bianca (E61) and now the LM (sort of saturated) I can say with 100% certainty that it makes an enormous different on output.

Hard to articulate any further than to say ‘try the different groups if you get the chance’. There’s also so many other factors at play with the various machines that group type is rarely the only factor in how a machine performs. Elizabeth vs Bianca for example, one has flow control, which is obviously another factor that can hugely impact the resultant coffee.

    Ernie1 have you tried blind testing espresso from LM and Bianca? Because HB did a somewhat informal test and Bianca won 5-3 to a professional LM. Not a strictly scientific approach but I think it is interesting to say at least.

    With that said I am not trying to see which makes better espresso, e61 vs saturated. It is more of a engineering curiosity. What can good/great E61 do in term of temp stability vs what a good/great saturated. It is alone not the only factor deciding espresso quality. I am just curious

      I had the Bianca for a year, and have had the LM for 11 months. I’ve probably drank over 500 shots from each. It’s not even close for me. That’s not to say the Bianca isn’t amazing, I loved the coffee had from it. So with all due respect, I’ll probably use that as my evidence rather than something I’ve read on the internet about what a stranger on the internet with different tastebuds thought.

      People choose E61s for various very valid reasons but I don’t think temp stability is one of them.

      I’ll say this though, if people spent less time basing their choices on what random people write on the internet and more on what they themselves enjoy, I feel like there would be more happy and fewer confused people.

      As I said I am not interested in what makes better espresso. This is about engineering curiosity. We average people don’t have the knowledge, experience, time and resource to validate every claim ourselves and we depend on the wiser like @DavecUK to make us somewhat more educated.

      Ok, I’ll wait for @DavecUK to tell me I do actually like the espresso from my machine…

      The E61 was released in 1961 (surprise) and the saturated group about 10 years later (presumably in a bid to improve the shortcomings of the E61). One is a large chunk of brass that’s entirely exposed, the other is inside a casing and constantly saturated with hot water. There’s a reason you almost never see an E61 in a commercial setting unless it’s there for aesthetic/heritage reasons.

      But yes, let’s wait for Dave, after all I’m just an ‘average’ person. Heaven forbid anyone just enjoys the drink in their cup these days in the endless game of spec sheet Top Trumps…

        Ernie1 i did not say anything of sort. You have every right to like whatever espresso you like. What I am hoping Dave to give insights to is how much difference the temp stability between e61 vs saturated is. Would it make a difference or it was blown out of proportion due to internet. You are making it very personally. I made it clear it is of engineering curiosity

            Totally depends what the e61 is attached to,

            If it’s on a hx machine Vs a dual boiler two very different machines

            After having the Evo which is a much larger chunk brass, you would be surprised how quickly a group looses heat.

            There’s too many factors in play than just the group temp, for instance the e61 and the lmlm both have very different water dispersion.

            Decent De1pro v1.45 - Niche Duo - Niche Zero - Decent is the best machine ever made -

              Cuprajake yeah for simplicity let’s compare DB with DB. I am aware that heat exchange can be quite a bit fluctuated with temp. Also implementation can affect the temp to which is why I mentioned good and great. I assume good is maybe 2°C fluctuation within shot while great is like 1°C?

              Interested to see if Dave has measurements he can share. He did mention that Bianca has great temp stability and Vevisius has very stable temp. Hoping to see some actual numbers. Even better if we have numbers from the like of Elizabeth or LM (but I think he hasn’t tested any LM, at least with published review, to date?)

                delta76 Apologies. I guess I just sometimes think people rely far far too much on the specs, the write-ups, the numbers, the reviews etc and can miss out on forming their own opinions sometimes.

                I’ve read comments in the past that almost seem like people are questioning their own beliefs and conclusions they’ve reached themselves just because some dude on a forum or YouTube has said something. And that’s really sad.

                    Scace is a great tool for this really

                    Decent De1pro v1.45 - Niche Duo - Niche Zero - Decent is the best machine ever made -

                      Ernie1 no worries. And I agree with you that for most people the most important thing is what in the cup. A good machine is a machine that make good espresso smoothly and repeatably. Period. But I consider myself to be a bit on a nerdy side. Understanding how machines work is exciting in its own way.

                      Cuprajake heard of it. The problem is that it is not exactly cheap. And I would have very limited dataset to make senses of it. Like I can measure my current Elizabeth and my future Bianca, but then what. I would need to measure quite many machines to draw a line where it is bad/decent/good/great. Fortunately for us internet is full of wonderful people who already have done that :).

                          I think Jake hit the nail on the head…there are various different groups and it really does depend on what they are attached to. Sure the e61 was designed in 1961…that doesn’t make it necessarily bad because of it’s age…look at the LSM spring lever group.

                          In the olden days, these groups were put on very different back ends…pipe sizes, thermosyphon restrictors, dual boilers and PIDs were not even thought of back then. These groups used sheer mass to make them work in the absence of all this stuff.

                          there are different types of “saturated groups”

                          • attached with a big duct (GS3 style)
                          • part of the boiler (Dalla Corte Style)
                          • ring group bolted to bottom of boiler (more conduction that saturated (although I have heard them referred to as saturated
                          • ring group (variants with heater cartridges)
                          • LSM Lever group with heater cartridges ala Evo or Nurri

                          Notice I have not mentioned the Micra group as it’s own category because it’s very, very, similar to the ring group concept, with a short water path to the group.

                          For me a true saturated group would be one where the entire group is double chambered, including where the portafilter locks in and is in effect a boiler as well….no bolt ons…so everywhere the portafilter and the water above it touches, is touching a wall, behind which is boiler water….so we don’t quite have those….although Dalla Corte comes very close as does LSM with heater cartridges (once it’s filled of course!).

                          The LSM has something the Dallacorte and others don’t a counter current flow when the group is filled and the ingress of close to brew temperature water (if desired). The counter current flow ensures an “stabilising” layer of water that gives up enough heat to even the temperature dynamic across a wide vertical area of the group. Otherwise a “relatively” significant temperature gradient exists. The group has now become almost a saturated group, being actively heated with 220W of power and water perhaps only needing a 1C touch up…no more cold water entering the system (as in a boiler) and no artificial disturbances of temperature sensors.

                          So modern technology and thinking coupled with a 1950 group….“possibly” gives the best temperature stability potential of all?

                          That said, an espresso machine and satisfaction is more than just about temperature stability…important though that might be.

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