Progressive vs. programmable??

[nicfortin]

If you have/had the choice which one would you choose and why?

Poll with that maybe


nic

[Weska]

That's kind of a poser, nicfortin. None of us really has that choice.

I did think about installing a little valve on the tube leading to my progressive piston so that I could cut it off. Problem was in arranging convenient access to it. If you had that arrangement on an S2, then you could have both pre-infusion systems in succession. The only other ways to compare are before and after installing (or uninstalling) the progressive or side-by-side with two otherwise identical Vivaldis.

Although I envy the S2 users with variable pre-infusion, I comfort myself with the idea that there are enough variables that freezing one and working with the others may be a blessing compared to opening another set of permutations and combinations with all the unavoidable ones. (This is also how I persuaded myself to use the automatic cut-off rather than stop the shot by inspection. However, I might go back on that decision at any moment.)

When you have limited numbers of shots per day to judge the results of changes, introducing more variables may be little more than frustrating.

That said, I would love to have the choice between my progressive pre-infusion and none as an either-or proposition because of JohnB's experience which seems to show that pre-infusion is not suitable for every bean and blend.

[wgaggl]

Got a preinfusion question for a machine I'm selling on the buy and sell forum, but I thought it's better to answer preinfusion questions here:

I'm a little confused by your original post viewtopic.php?f=16&t=1192, did you install and uninstall the preinfusion on your machine...and if so why? I'm presently trying to decide between and a Vivaldi and a Vivaldi II...and was curious how much the new upgrades really matter to a newbie.
-jdg

For my own roasts I decided that I didn't like it, I had to increase the temp by one step to get it similar, but it changed the flavor profile (sometimes that's a good thing). You will find on that forum people who really liked it, some who dislike it, some that really didn't see any flavor differences.
For the S1 V1 you can have progressive preinfusion, that's physically installing a springloaded preinfusion chamber. I have gone back and forth several times, but it does involve opening up the machine, and eventhough I guess I can do that now in less than 15 minutes, it's not convenient to change that based on the coffee you are brewing. But even for pump-driven preinfusion with the VII (please see edit note below) you will see that opinions vary, many have it set to a really low time if they use it. Personally I like progressive preinfusion (with the chamber, water flow builds up gradually) better than pump driven preinfusion (in which the water is left to sit around for a while to cool down a degree or two in that passive Vivaldi group). I do think that progressive preinfusion is somewhat more forgiving than pump-driven in terms of channeling (I rigged a precision timer to try that before buying the preinfusion chamber), but with a conical grinder that matters even less.

Edit: As JohnB pointed out in a message below, the VII has line-pressure (aka pump-delayed) preinfusion. Im sorry for the mixup that's the fault of my GS3...
In my response (message after JohnB below) I clarify that I actually did both pump-driven and pump-delayed, as the timer module allowed for that.
Pump-delayed like the VII had quite similar results in (channeling and flavor) to the preinfusion chamber added to my original S1. I tried to keep the preinfusion times similar between the different methods. The pressure profile are of course quite different, and line-pressure preinfusion depends on the pressure set on your regulator. That is another topic for discussion by itself.

Wolfgang

[JohnB]

But even for pump-driven preinfusion with the VII you will see that opinions vary, many have it set to a really low time if they use it. Personally I like progressive preinfusion (with the chamber, water flow builds up gradually) better than pump driven preinfusion (in which the water is left to sit around for a while to cool down a degree or two in that passive Vivaldi group). I do think that progressive preinfusion is somewhat more forgiving than pump-driven in terms of channeling (I rigged a precision timer to try that before buying the preinfusion chamber), but with a conical grinder that matters even less.

Wolfgang

The S1V2 does not have "pump driven" pre infusion it has line pressure p/i. The GS3 uses pump driven p/i & I haven't heard any owners raving about it. Programmable line p/i is as good as it gets until you get into manual paddle control. Along with being able to set the p/i pressure & duration you also have the option to just turn it off. The "canned" p/i of the S1V1 & Mini offers none of these options, hence I would not install it on my machine.

[wgaggl]

The S1V2 does not have "pump driven" pre infusion it has line pressure p/i. The GS3 uses pump driven p/i & I haven't heard any owners raving about it. Programmable line p/i is as good as it gets until you get into manual paddle control. Along with being able to set the p/i pressure & duration you also have the option to just turn it off. The "canned" p/i of the S1V1 & Mini offers none of these options, hence I would not install it on my machine.

Hey John,
I'm laughing about myself now, really!
Yes, the GS/3 has pump driven preinfusion, thanks for the reminder, I'm a new GS/3 owner (that's why I'm selling my S1) and I'm already talking about pump driven preinfusion! Geez, that didn't take long to confuse myself?

Anyways, with a timer module from Omega I tried actually 2 things with my S1:

1) Pump-driven preinfusion (sorry, that's GS3)
2) Pump-delayed preinfusion (aka line-pressure preinfusion like the VII)

and compared it to the preinfusion chamber.

The pump-delayed preinfusion like the VII wasn't really different from the pre-infusion chamber in my experiments.

Sorry for the mixup, that's really GS3 thinking (soon Chas will label me as S1 traitor, I guess...).

Wolfgang

[JohnB]

What line pressure settings & durations did you try with the pump timer delay? Any idea what p/i pressure the can uses?

[Richard]

Preinfusion really is a matter of personal preference and probably the coffee you are using.

For my own roasts I decided that I didn't like it . . . .

I found that for certain coffees (all light-roasted "Northern Italian" style) with ca 14 gram doses, programmable, line-level preinfusion was detrimental to flavor and oftentimes made an erratic pour. So for those coffees dosed in that manner I simply turned it off.

For other coffees (mostly darker roasted) dosed in a 16-19 g range, I found a few seconds' line-level preinfusion helping with an increased clarity of flavor and more consistent pours.

But as you say, personal preference needs to prevail.

[wgaggl]

What line pressure settings & durations did you try with the pump timer delay? Any idea what p/i pressure the can uses?

I think I need to learn to use preview (had to delete a post, and back-edit another...).

I tried to keep the duration similar to the PI chamber first, started at 2s and went up. I also realized that the static pressure buildup measured by the PF pressure gauge was different than the actual gradient with water flow through the coffee, so there's some variability right there (the V1 doesn't come with a built-it group pressure gauge).
The line pressure was set to 2.5bar, I recognize (as written in my edit above, sorry for back-editing) that the results also vary by line pressure. However, I didn't investigate different line pressure settings.

One thing I didn't like about longer preinfusion times, especially for some light roasts (like a city) the longer the preinfusion time, the more pronounced were sour and fruity notes during the first third of the pull. I ended up going up with temperature, which actually decreased the buttery notes in the flavor profile.

On some darker roasts it actually brought out more detail.

I went through a lot of coffee before I decided I didn't like it.

I'll check my notebook when I get home tonight for some more info,
Wolfgang

[wgaggl]

I found that for certain coffees (all light-roasted "Northern Italian" style) with ca 14 gram doses, programmable, line-level preinfusion was detrimental to flavor and oftentimes made an erratic pour. So for those coffees dosed in that manner I simply turned it off.

Richard, I just saw your post after I hit submit on that message one down from yours and your statement describes it well.
Did you also play with the temperature when selecting preinfusion?

W.

[JohnB]

As I've posted before my favorite feature of the p/i on the S1V2 is that I can turn it off when I don't want to use it. I do like having it & I use it on larger doses/commercial blends but for my 13-14g S/O shots I turn it off.