Prototype La Marzocco GS3 - A Pro's Perspective - Page 2

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malachi (original poster)
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#11: Post by malachi (original poster) »

1 - you can program the pre-infusion, yes. i have not explored the limits.
2 - i don't seem to need a flush routine, other than for cleaning purposes. i tend to flush about 0.25oz before i begin making shots, but that's mostly habit. i'm in the middle of doing measurements and will post full results but so far it's looking really (really) impressive.
3 - pump is near-silent. in fact, the whole machine is incredibly quiet.
4 - no. in fact, i have it programmed to automatically shut off at 4pm each day and turn on at 5am each day.
What's in the cup is what matters.

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malachi (original poster)
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#12: Post by malachi (original poster) »

barry wrote:a mini-rotary pump would be cool.

maybe mark b. can put in one for each group on the synesso.
this machine has a very small rotary pump. i don't know what would qualify as a "mini" pump so i'd hesitate to call this such a beast.

i think "pump-per-group" is a great concept.
What's in the cup is what matters.

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malachi (original poster)
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#13: Post by malachi (original poster) »

Abe Carmeli wrote:0.6 secs is very short for preinfusion, as compared to a vibe on most E61 machines doing 4-5 secs.
Keep in mind that this is not the slow, progressive ramp-up pre-infusion that you're talking about. This is "pump-pulse" preinfusion, where the pump turns on briefly and then off before going back on for extraction.

Also, keep in mind that this pre-infusion is not measured from when you start extraction to when you see espresso, but rather the duration of "on" time for the pump in that initial pulse.

I've gone to a 0.8sec pre-infusion now for experimentation purposes. We'll see what the differences are.
What's in the cup is what matters.

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barry
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#14: Post by barry »

malachi wrote:I've gone to a 0.8sec pre-infusion now for experimentation purposes. We'll see what the differences are.
fwiw, a long time ago, someone explained to me that "proper" pre-infusion was just enough water to saturate the puck, but not so much as to cause the coffee liquor to emerge. as you can accurately control the pump-on time, i would suggest increasing the time until you first see some drops coming from the bottom of the basket, and then back off a tenth of a sec and use that as your preinfusion setting. it's sort of like setting the "proper" grind for drip: go finer in steps until a hint of bitterness is detected, and then go coarser one step.

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another_jim
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#15: Post by another_jim »

malachi wrote:It's a rotary pump machine - no doubt about it.
Cool; now I'm seriously interested. Also I'm glad Bill got his brainchild realized without any compromises (the wait for the paddle wheel style semi-auto was announced at the SCAA -- at that point the plastic group cover gets much prettier)

I think we seeing history in the making here. Obviously, at the target price, this is not a home machine. But the size and convenience, i.e pourover, 110volt, easy kitchen counter fit, make it a home machine. However this does in the market, I expect all the innovative stuff in it (including the technique of packaging large boilers in a small frame) to "trickle down" to other machines.

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malachi (original poster)
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#16: Post by malachi (original poster) »

About the plastic cover...

I understand why it's there (liability and to provide a visual language link to the semi-auto version). And I have to agree I don't like it much.

That being said:

1 - I gather that it may also be changing between current prototype and final product, and
2 - I discovered that it can be removed.

If this were my machine, I'd remove the plastic cap and just use a grinder to get rid of the threaded stud it is attached to. This would give me the "Kees-style" naked group.
What's in the cup is what matters.

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malachi (original poster)
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#17: Post by malachi (original poster) »

another_jim wrote:Also I'm glad Bill got his brainchild realized without any compromises .
Bill has done an amazing job.
There are so many things about the machine that show his genius.

You are very right - it is without compromise. And I'm really, really glad that is how it ended up.
Yes - it means that it's expensive.
But in this case I think that it's a worthwhile trade-off.
I think this is an important machine.
What's in the cup is what matters.

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malachi (original poster)
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#18: Post by malachi (original poster) »

Shot Quality

I'm mentioned the quality of the espresso a few times before - but I'm going to go into a little more detail in this post.

Right now I'm going based on two espressos only. The first was an experimental blend from Andrew Barnett of Ecco Caffe. This was a very sweet and rich coffee, heavy in pulped naturals, which performed best at higher temps and with a down-dosed triple basket. The second is the espresso from Hines Public Market Coffee. This is a complex coffee, with tons of fruit and lovely chocolate notes, which performed best at a mid-point temp and with a very slightly up-dosed double basket.

First of all... with this machine, both coffees were reproduced beautifully. The coffees showed incredibly well.

There were some commonalities between the two espressos as shots. First, in both cases there was a dense, syrupy feel to the shots. There was a level of "concentration" of flavours that I'm used to getting in good shots off commercial machines. Secondly, the elusive "clarity in the cup" was present in both cases. This is a "distinction" and separation between the various flavours that allows you to taste the complexity of all the coffees that go into the blend - rather than one overall blended flavour. Third, in both cases the aftertaste was incredibly long-lasting. I think this is at least in part due to that dense mouthfeel and intensified, concentrated flavour profile. Finally, the crema produced from both espressos was noticeably tight and long-lasting.

There were also some differences in how the coffees were reproduced.
With the Ecco Caffe, there was a slight "damp paper" note that I had not tasted when prepared on an E61 machine. This was a subtle note that had been hidden before and which now became distinct. Obviously, this was not a desirable flavour to find. At the same time, the chocolate flavour in the coffee expanded and became incredibly complex - revealing itself to actually consist of a range of flavours (dutch processed cocoa, Belgian dark chocolate and even a little touch of vanilla and cocoa butter).
With the Hines espresso, the sweet fruit (strawberry, dried blueberry and passion fruit) became incredibly pronounced. As with the Ecco Caffe, I was able to taste more complexity in the chocolate tones - which also had the effect of "widening" on the palate and becoming very heavy. This balanced out the enhanced fruit flavours nicely.

So far, I'm finding the shots from this machine to be less like what I'd get from a Linea than what I'd get from the temp-stabilized, PID'ed Mistral.
What's in the cup is what matters.

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malachi (original poster)
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#19: Post by malachi (original poster) »

Abe Carmeli wrote:Chris,
have you tested temp accuracy with the Thermofilter?
Just finished first testing session. Assume the following is VERY preliminary.
My tentative initial numbers are looking like no-flush ±0.3F. (correction: total swing is 0.3F)
Note that the PID has not been tuned.
I really need at least two more days of testing and some tuning before I have conclusive numbers, but the goal I would love to see is ±0.15F.
What's in the cup is what matters.

Abe Carmeli
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#20: Post by Abe Carmeli »

malachi wrote:My tentative initial numbers are looking like no-flush ±0.3F.
Thanks Chris. A second by second graph would be more telling than a final number. It would be nice if you could post a few shots once you've concluded the PID tuning. And by the way, does the PID have an auto tune, and does it use Fuzzy Logic ?
Abe Carmeli