Fiorenzato Bricoletta - A Pro's Perspective - Page 3

[malachi]

Discussion of "clarity" and pressure/temp moved to new thread in Barista Tips.

[malachi]

mmm mmm good


a wonderful shot (half consumed pre-photo)

[Abe Carmeli]

I checked brew pressure on the machine and it was higher than I like (10.25BAR)

Chris,

How did you measure Brew pressure? Using a P/F gauge? if so I assume you measured it with no flow. If so, during a shot, the pressure will be different ~ 1 bar lower on a 25 sec 60 oz flow. so the 10.25 bars with no flow, actually translates to ~ 9.25 bars during a shot

[malachi]

I borrowed a trick rig from the Stumptown tech crew that mimics both resistance and flow rate (which I suppose are the same thing you could say) and shows pressure.

You have seen a full BAR difference on the gauge fitted portafilters? In my experience it's been a lot less than that (more like 0.5BAR to at most 0.66BAR).

Hmmm... Actually, let me run over to the roastery and verify those numbers.

[Abe Carmeli]

I borrowed a trick rig from the Stumptown tech crew that mimics both resistance and flow rate (which I suppose are the same thing you could say) and shows pressure.

You have seen a full BAR difference on the gauge fitted portafilters? In my experience it's been a lot less than that (more like 0.5BAR to at most 0.66BAR).

Hmmm... Actually, let me run over to the roastery and verify those numbers.

I tested it on Vibe pumps, but not on a rotary. On a vibe it is ~ 1 Bar. That is: 10 bars with no flow will become 9 bars with a flow of 2 oz in 25 seconds.

So that I fully understand, what flow rate did you use when you reduced brew pressure to 9.25 bars?

[malachi]

Just got back.
On the Linea the PF fitted gauge reads almost exactly 0.66BAR high (as compared to both the rig and the in-machine gauge).

Honestly, I don't know what they've got it set to but would have to guess (given the Stumptown parameters) that it is 1.75oz in 27sec.

[malachi]

In order to continue my tweaking for experimentation on this whole clarity/temp/pressure thing, I decided it would be best to turn the Bricoletta (temporarily of course) into a "skeleton" version. I thought you all would dig the photos (grin).

[malachi]

Hey Abe.... to further complicate things I borrowed a different PF fitted gauge from the S-town techies and this one reads a little over 0.8BAR high on the Linea.

D'oh...

[Abe Carmeli]

Hey Abe.... to further complicate things I borrowed a different PF fitted gauge from the S-town techies and this one reads a little over 0.8BAR high on the Linea.

D'oh...

Chris,

I found that fluctuations in voltage greatly affect brew pressure at least on a vibe pump. 5 volts fluctuation will produce ~0.3 bar difference. I don't know how it applies to rotary pumps though. On my home Machine I use a variac to reduce voltage from 115 to 100 volts and saw 1 bar difference in brew pressure.

[malachi]

I doubt that would explain it.
I had the two PF gauges side by side on the Linea and saw the same results test after test. I fear at least one of the gauges is inaccurate.

[lennoncs]

I fear at least one of the gauges is inaccurate.

The question is...which one?

I feel your pain...it is a common beef I have with many suppliers of "instrumented" equipment, it is not instrumented per se but just has a cheap gauge on it.



sean

[malachi]

Given that neither read actual brew pressure (since there is no flow) it's pretty much impossible to know. The good news is that I don't have to use either (grin).

Then again, I do wish the Bricoletta came with a brew pressure gauge.

[AndyS]

I found that fluctuations in voltage greatly affect brew pressure at least on a vibe pump. 5 volts fluctuation will produce ~0.3 bar difference. I don't know how it applies to rotary pumps though. On my home Machine I use a variac to reduce voltage from 115 to 100 volts and saw 1 bar difference in brew pressure.

A 5 volt variance won't affect rotary pumps, but will, as you observe, change the output of a vibe. That is how, using a variac, Jim Schulman tested brew pressure profiles on his home machine.

[terryz]

The Horror.

Chris Tacy has become a techno coffee geek!

Save yourself man. Put the body back on that machine and get back to the coffee!

Next thing I know you going to be hanging out in my basement tearing things apart (Wait, that actually could be a good thing). Carry on.

So tell me more about your PSI and temperature Mr. Tacy........

[Abe Carmeli]

Given that neither read actual brew pressure (since there is no flow) it's pretty much impossible to know.

Chris,

I tested the brew pressure differences using you parameters 1.75 oz in 28 seconds, and I believe your 0.8 bar difference reading may be the accurate one. My reading was 0.78 bars difference. Again, this was done on a vibe pump.

[malachi]

So I spent a long time over the last couple of days trying to figure out if there is any consistent difference in results with changes in brew pressure across many coffees.

It's been very frustrating.
The whole methodology for adjusting/managing brew pressure is far too inaccurate and mechanical.

That being said, I have to say that the ability to dial the brew pressure in with any degree of consistency is a huge win with this machine. I've always been frustrated by both the mechanics and the results with vibe pumps (yes, I know that there are ways to stabilize and manage vibe pumps far better but I'm not practiced with them). It's incredibly nice to be able to just dial the pressure up or down and pull shots, taste, dial some more.... It's not only fun to experiment in this manner - it's also incredible to have this additional control.

While I may not be learning as much as I would like right now, I am getting to drink some truly fantastic espresso. Yes... there are obviously compromises and it's not fair or accurate to say that the Bricoletta is "as good" as something like the Mistral or Synesso. But the ways in which it is "not as good" are often more abstract (ergonomics) or convenience related (HX vs double boiler) or irrelevant to me (yeah, I can't easily steam 20oz of milk like I can with a commercial machine).

Sure... the Bricoletta is harder to get great shots out of than a Synesso. But if you have the skill, the shots are just as good. The milk is just as good. The drinks are just as good.

And that, that is amazing.

[AndyS]

So I spent a long time over the last couple of days trying to figure out if there is any consistent difference in results with changes in brew pressure across many coffees.

It's been very frustrating.
The whole methodology for adjusting/managing brew pressure is far too inaccurate and mechanical.

That being said, I have to say that the ability to dial the brew pressure in with any degree of consistency is a huge win with this machine.

Good timing for your post. I just got off the phone with John Bicht from Versalab. Coincidentally, he's been doing some experiments with brew pressure on his M3 espresso machine (which provides electronic brew pressure control). He previously said that changes of 0.1 bar in brew pressure were distinguishable, but now he thinks that 0.05 bar may produce a noticable difference.

[malachi]

The review is nearly done...

If anyone has any final questions, things they would like evaluated or points they would like examined in the review... speak now or forever hold your peace.

[malachi]

One thing you may have noticed in this review is that I've never posted any pictures of the steam wand.

Well... the Bricoletta provided for this review was an early version of the new and improved Bricoletta, with a new style of wand.

I'll post pictures tomorrow.

In the meantime... It's been fun!!

[malachi]

And it all comes to a close.

The review is now up on the site.

It's been really fun.

To sign off... here are some final photos of the machine.

First - to illustrate my "art deco" comments...




And, per my promise, some shots of the new, improved steam wand. I think this is a Cimbali set-up (which most people consider to be one of the best out there).








Thanks so much for all your input, support and involvement.
It's been fun.

For future comments, check out the Article Feedback thread.