ACS Vesuvius Evo Leva - Page 51

A haven dedicated to manual espresso machine aficionados.
User avatar
espressotime

#501: Post by espressotime »

coffeeOnTheBrain wrote:I know the name, but not what you ate aiming at. Would you elaborate on this or point me in the right direction.
Bosco had a little reservoir situated right at the group.

DaveC

#502: Post by DaveC »

coffeeOnTheBrain wrote: Basically the first triple heater machine with only one group, except the ACS ;)
Which makes it basically the second triple heater machine with only one group, does it not? :wink:

One interesting thing to think about with all the extremely interesting approaches that have been taken, I'm thinking about the KVDW machine Idrocompresso saturated group here, is certain comments a while ago about stable temps in a Lever group. When the Evo first came out people were complaining (without merit IMO), that it was very stable on brew temp during the shot and that this was a bad thing. I actually completely disagree as I think that this stability is a good thing. KVDW seems to take the same approach, valuing stability rather than the rather large temperature decline during the shot of some machines. When I spoke to him in 2019 at Milan, stability during a lever shot was also mentioned.

Now I'm not saying a small decline in temperature during the shot is not an interesting feature, but that decline needs to be small, I would say 3C or less....which "might" reduce bitterness in a shot. Although the Evo can do declining or increasing temps (which are probably of no value) during the shot. I think stability should be an overriding aim in the design.

With the other dual boiler lever I am helping out with (nothing to do with ACS), a key design objective (because it's a twin boiler thermosyphon design) is to keep any offset as small as it can be...this is technically difficult because the Fiorenzato Piazza San Marco style groups require a lot of energy, they are massive and loose the energy quickly. The larger the offset, the bigger potential for a thermal drop during the shot....coupled with initially overly hot water on the puck.

User avatar
espressotime

#503: Post by espressotime replying to DaveC »

I don't know if this is true.Maybe it is. I go by taste and don't care much about the technical side of things. To me levershots taste softer than pump shots. I don't know if tat is due to the temp. drop or pressure drop.To me the shots from my Lambro are much better than them from my Pompei.I guess that is caused by the spring pressure. Or maybe it is the different basket size. I don't know.Ponte Vecchio shots tasted great to me too.

DaveC

#504: Post by DaveC »

espressotime wrote:To me levershots taste softer than pump shots. I don't know if tat is due to the temp. drop or pressure drop.To me the shots from my Lambro are much better than them from my Pompei.I guess that is caused by the spring pressure. Or maybe it is the different basket size. I don't know.Ponte Vecchio shots tasted great to me too.
I think it's a combination of things...certainly pressure drop and basket diameter are important factors. I have to think about the science because there always needs to be a rationale in design. Otherwise it's really difficult to know what improved things and how to move forward. So I don't have the luxury of not knowing why it might test better if such and such is done. Anything else starts becoming "magic" for a designer.

It's the same with grinders and roasters, if we don't know what's making the change, we don't know how to improve things.

Primacog

#505: Post by Primacog »

DaveC wrote:Which makes it basically the second triple heater machine with only one group, does it not? :wink:

One interesting thing to think about with all the extremely interesting approaches that have been taken, I'm thinking about the KVDW machine Idrocompresso saturated group here, is certain comments a while ago about stable temps in a Lever group. When the Evo first came out people were complaining (without merit IMO), that it was very stable on brew temp during the shot and that this was a bad thing. I actually completely disagree as I think that this stability is a good thing. KVDW seems to take the same approach, valuing stability rather than the rather large temperature decline during the shot of some machines. When I spoke to him in 2019 at Milan, stability during a lever shot was also mentioned.

Now I'm not saying a small decline in temperature during the shot is not an interesting feature, but that decline needs to be small, I would say 3C or less....which "might" reduce bitterness in a shot. Although the Evo can do declining or increasing temps (which are probably of no value) during the shot. I think stability should be an overriding aim in the design.

With the other dual boiler lever I am helping out with (nothing to do with ACS), a key design objective (because it's a twin boiler thermosyphon design) is to keep any offset as small as it can be...this is technically difficult because the Fiorenzato Piazza San Marco style groups require a lot of energy, they are massive and loose the energy quickly. The larger the offset, the bigger potential for a thermal drop during the shot....coupled with initially overly hot water on the puck.
I am not sure if I am understanding correctly of the owner of the Lambro on the following post but he seems to be saying that he had tested the temperatures of his machine and from preinfusion to the end of extraction there was a drop in temperature of 6 degrees Fahrenheit. So if the Lambro really does taste better, could it be that this temperature drop throughout the extraction process could be part of its secrets?

Faema Lambro Brew Temperature
LMWDP #729

User avatar
Jeff
Team HB

#506: Post by Jeff »

A quick reminder that one needs to be careful of assuming that correlation and causality are the same thing. https://www.tylervigen.com/spurious-correlations

That warning out there, with machines that can control temperature during the shot keeping the other variables reasonably constant (they all interact, even if just due to the change in viscosity or speed of extraction), there is a preference among some users for declining-temperature profiles.

coffeeOnTheBrain

#507: Post by coffeeOnTheBrain »

DaveC wrote:Which makes it basically the second triple heater machine with only one group, does it not? :wink:
...
Yes, you are right :D
And here I am before I read your post and hoped you would have commented on the second cylinder to fill the actual cylinder idea ;)
It does sound funny but I don't find the idea that bad. It might not even need a second lever but could be spring loaded and since that spring only needs to produce 1-3 bar it could be loaded by the main spring when releasing it. It might even be used to smooth the pressure curve of the main spring.
Ok the mechanics might be almost as complicated as a mechanical watch but is that a bad thing. I mean who doesn't love the mounting of a Conti lever with it's bazillion pivot points.

Cuprajake

#508: Post by Cuprajake »

Thing is. Without burning through a bag of beans it's hard to say.

I'm almost tempted to buy a kilo of a med/light and try

Flats, dropping, raising temps then also different group and boiler temps.

I know some like Denis said they changes temps to quite extremes but the grinder also made a massive difference in what extraction temp was needed.

Idfixe

#509: Post by Idfixe »

I stopped when I saw the red dial... perhaps I should have tried.... I did the opposite (hold the lever) which did (sometines) good results

Cuprajake

#510: Post by Cuprajake »

presume you dont need to do the pumping with a modern lever