Londinium R24 vs. ACS Vostok - Page 8

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#71: Post by Primacog »

The Bone Ranger wrote:Gees, we were doing so well fleshing this out. I don't know how from my posts you can say that the above is what I am suggesting. We can do better here than creating straw men.

I own an R24, and am having a terrific time, but I am not here arguing for it. Before purchasing, I looked at some of the levers like Nurri (before they were officially released) and ultimately decided to go with the proven product, and wait to see what results the early adopters had. And my machine was used, local, and priced right.

I'm not suggesting for a second that one of these hybrid levers is not more versatile. I am asking why, if controllability of these details is important to the purchaser, are they content with the pressure profile of the spring being largely beyond their control?

Is it because of tactile nature of this machine versus others with screens?

Is it because the spring profile is the superior pressure profile for most every bean?

If it is because 'taste this and tell me I'm wrong'?

Is it because the extraction pressure doesn't matter as much as the other aspects these machines can control?

Is it because 'I've loved my other spring levers, so wanted one with more?
I was trying to understand what u were saying and if I have misunderstood you, my apologies.

The profile of a spring lever is a significant cause of why they tend to taste good to most people. So that is of course something all of us fans of the lever want and surely do not want to do without and is the reason why we love levers. What we r discussing in this thread is going the extra mile to further improve on that profile in terms of how to optimise the water temp and pressure of the water to the beans concerned.

Therefore if the spring lever profile is 50 per cent of the equation (completely arbitrary number), my understanding is this thread is discussing what the lr 24 and hybrid levers like the Nurri offer to get the remaining 50 per cent.
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#72: Post by Primacog »

Jake_G wrote:I think the fill rate is what gives you the column.

I thought the crazy fast fill rate must be doing bad things, but it just doesn't seem to be the case.

Remember that there is no column of water until the fill rate makes it. When the piston is raised, there is just empty space until the ports are uncovered in a traditional lever. Only when the piston seal clears the port does the column of water begin to be formed. So being that the entire column needs to be filled, perhaps the effective fill rate is not so huge.

Take a decent with a 20ml headspace (I know I'm wrong, but bear with me) and an 8ml/s fill rate. You get 2.5s to fill.

Then take a dipper or HX machine that utilizes flash boiling plus pump assist without a gicleur to have a very high fill rate. But you also have a 100ml swept volume to fill behind the shower screen and a typical headspace to fill between the shower screen and the puck. So if you have a 50ml/s fill rate, you still have 2.4s of fill time for a total volume of 120ml.

Not so different.

Why do you say "particularly the LSM ones"? Do they have a bigger column of water than other levers?
I always thought that the LSM grouphead has especially greater volume instead the brew chamber since we easilt get double espressos for every pull. This was more an assumption picked up somewhere since I have no experience pulling shots from any other lever type.
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#73: Post by Cuprajake »

All these levers from my londinuim l1 have tech in them, infact the pressure stat broke on my Londo and I had to replace that and the safety valve. It also has a gicar box

As does the nurri/acs

The lr24 has Bluetooth modules and thermersitor, so there no more or less tech in any of them

If you want low tech get a pavoni

I've just gone mains fed on the Evo which means a slower fill with all things the same, I will give it a week to see if I see changes.

The gear pump in the Evo runs at 4000rpm and it instant so has a very quick fill

Gear pump
And mains fed
Please note, same dose, same bean same settings.


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#74: Post by Jake_G »

Primacog wrote:I always thought that the LSM grouphead has especially greater volume instead the brew chamber since we easilt get double espressos for every pull. This was more an assumption picked up somewhere since I have no experience pulling shots from any other lever type.
Ah. Nothing special there. Felinis are for small "home" levers like direct levers, the various clubs or the Elektra MCAL. All other spring levers are dubbed as "commercial" groups and have no problem pulling doubles. This would include Londinium, Bosco, Faema, Gaggia, VA, etc...
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#75: Post by Primacog replying to Jake_G »

Ah OK- it was a false dichotomy that I had drawn then need on home levers.
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#76: Post by Jeff »

An interesting set of observations from the DE1 experimentalists with lighter roasts is that PI pressure can impact the perception of "chocolate" vs more subtle, distinct flavors. This is with the other extraction parameters held reasonably constant.

Whether you believe that the DE1 can successfully emulate any other machine is not relevant to that set of observations. What is noteworthy for me is that being able to explore more of the extraction space in a controlled way can lead to greater insight. In turn, those insights can shape practice with whatever controls you have on the machine in front of you at the moment, one knob, three, or none at all.


#77: Post by DenisSabou »

My findings and other people findings with decent espresso did not translate to others machines unfortunately (for some reason).

When having formed an opinion about grinders and how they are (chocolate niche) after swapping the Decent with a ACS evo leva the niche was everything but not chocolate anymore. Is it the high flow, the group, I have no idea but a grinder on ACS will not taste the same as on a Decent with any profile you want.

So I would be really skeptical when it comes to general observations based on a Decent. I can give you a simple question why things are not working normally. Some of their findings can't even be applied or replicated on a simple e61 Lelit Bianca machine.

On the ACS I measured my grouphead flush temperature by drilling a basket putting a dense sponge inside with one 1.5 mm profesional thermocouple used in roasting with phidget. I found out that to achieve a flushing temperature of 99-100C I need ± 96C on the group and 104C on the brew boiler. This was shown be the probe in artisan, several times and also I saw this that while flushing with nothing in the group there was steaming and hissing coming out.

Now when I had the Decent I would always pull on big ssp flats 88-89C starting temp with a 2-4C decline during the shot, and would always use the same or a tiny bit 1C hotter for the niche on the Decent.

Now after receiving the ACS and playing with it I found myself pulling at 95C brew temp on Niche/93C on Bentwood or 90/91C on Big ssp flat. So how do you explain that?

Yes I have tried 95-98C shots on Niche on the decent and they were bad, but for some reason on the Lever they work, and I measured the temperatura at the grouphead just like on the Decent not the brew boiler temp.

There are many mysteries that we dont know the answer for, and without experimenting and playing around we would never find or try new things. I ditched my 1st niche when I had the Decent because it was bad flavor/aroma wise, but after going on a trip to Italy at Gardelli's coffee shop I had 2 amazing single dose espresso from his single origin ethiopia and kenya and that convinced me there was nothing wrong with my Niche, and the boring chocolate taste is not due to the grinder but to the machine/profiles, so I got a second Niche with the lever and the cups started to sing with light roasted coffee.
On the decent on normal shots (we are not talking here of blooming or allonge) I would hit 19-20% EY on the ACS EVo and niche my first shot was 24%+ EY already, aprox the same brewing times.

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#78: Post by pj.walczak »

IMHO, another significant difference between those two machines is the group.
They have different diameter, and very different pressure profiles.
Would be great to hear more about those.