Water Debit on Bricoletta

[Grant]

As a followup from Cannonfodders "Flow rate of a rotary pump espresso machine" thread, I have to wonder if I find myself in the same situation with my Bricoletta. After purging the hissing water and getting a steady stream, I am getting just a bit less than 5oz of water per 10 seconds, which seems far too high by what I read.

So, I guess an initial question is how can you check the gicleur/jet size in a Bricoletta if appropriate?

As a second question, where can you purchase alternate sized components to test/play with?

Grant

[cannonfodder]

I ordered my jet from EPNW. I do not know if they carry a set that will fit a Bricoletta, you would have to call or email to find out, unless Terry or Dave sees this thread first. If you do a search on EPNW for keyword jet you will get the list.

Interesting how much conversation evolved from one simple question. One reason I like HB so much. Lots of insight with very little noise.

You could always take the jet out and use a feeler gauge to size it.

[Grant]

OK...I did the "jet" search, and it comes up with a nice list of parts. While I am pretty mechanical (and electrical) and have no fear taking anything part, I can't even begin to think where the jet assembly gets changed, removed, or how to get in there. Is the jet and related in the group head area (i.e. under the dispersion screen?)

Grant

[HB]

Is the jet and related in the group head area (i.e. under the dispersion screen?)

Lino has a nice diagram and explanation in E61 Group Espresso Machine: Detailed Interior Schematics:

Here's the close up of the brew path.

The water entry should be obvious, then it travels up, thru the bright green section, thru the filter screen (transparent grey), down thru the gicleur (yellow), into the valve section (blue). The valve is shown closed.

When the orange cam rotates up (it's attached to the lever), it pushes up the valve seal (yellow) and brew water floods the cam area, then goes up towards the infamous allen screw. (Now it should be apparent why it's there as well. It would be hard to drill around that corner.)
Then down toward the dispersion disk.

Jet = gicleur.

[Grant]

AAhhh....I see. Excellent...thanks. So from the looks of it, I take out the "mushroom" (I have done that already a couple time for curiosity's sake and to check for scale), and then furthermore, it looks like the mushroom breaks down further. *Seems* simple enough....I just rejetted a carb on my Vulcan, so this should be easier if I can find the parts (or even need them).

Grant

[lino]

*Seems* simple enough....I just rejetted a carb on my Vulcan, so this should be easier if I can find the parts (or even need them).
Grant

Actually you don't even need to take out the mushroom. Just remove the smallest bolt on the top and look down. You'll see the top of the gicleur. It's got a hex head, so just find the right socket or nut driver and you're good to go. Should be much easier than jetting a motor cycle carb, and you will almost certainly not smell like gasoline when you're finished with this job.

Finding the parts could be another story however. I've never seen different jets available -- never looked either. Bigger would be easy -- just a few minutes with a drill bit away, but smaller may be a challenge.

ciao

lino

[Grant]

So after going home last night and pulling the bolt on the top of the mushroom and pulling the gicleur, it appears to my eye that the jet hole is smaller than 1mm in diameter - perhaps in the .5 or .6 range as "recommended" may be more appropriate. I may order some other ones to play around with anyways in case my eye balling is our of whack, but it would seem my gicleur is suitable to obtain the desired gentler preinfusion.

Disclaimer...all the following is based on the assumption I am dosing, distributing, tamping etc. correctly. I am really hoping the problem the problem is NOT on the handle side of the PF. I have spent many, many hours on technique, consistency etc. Coffee freshness is not an issue (from hours old to 10 days old tested). Macap M4 handling the grinding duties. Still getting highly variable extraction results.

Anyways...so this had me thinking that if it is not the gicleur causing the fast rush of water/puck disturbance/fast extract/early blonding, than what is it? I posted some questions on CG some time back about what effect input pressure to the machine has, but received no responses...it left my mind until recently based on threads here. So, back into the basement I went to where my water system is, and I reduced the input pressure to the machine to 20psi (I think...see questions below). Tested brew pressure again...a bit lower than the 9bar previous setting...about 8.2 bar I believe so I will ramp that again up later...didn't feel like pulling the case off the Bricoletta.

Did a series of test shots, and somewhat surprisingly...instead of the very consistent 4 second times to the first drops to appear and the struggle to prevent early blonding, it is up to about 7 seconds before the first drops appear, and the resultant extractions are obviously superior and more consistent than anything previous. 5 Shots in a row, lightening of the flow didn't even begin to show until at least 20 seconds in, and it felt like I could extract forever (compared to previously) before blonding. Taste was excellent..just a hint of bitterness that fit in perfect with the chocolate (a yemen blend - 3 days old).

EDIT: Oh yeah...forgot to mention....with the only change being the input line pressure, water debit is now about 100ml/10 seconds, down from almost twice that amount previously.

So...I guess this leads to some more questions...particularly with the Bricoletta and input pressure. My Bricoletta is the rotary version, and also the volumetric controls. Water config:

WATER LINE ---> WATER SOFTENER ---> 5 MICRON FILTER ---> PRESSURE REG ---> BRICOLETTA

1) Does having volumetric controls make any difference as opposed to a lever when it comes to extraction? i.e. do the electronics typically emulate lever usage?

2) Input pressure. Does input pressure effect preinfusion, again..with a rotary pump and volumetric controls. From my testing last night, it certainly seems to. Just looking for confirmation or some validation as to what I have done seems valid. Does the improved extraction and longer extraction times seem appropriate, just from dropping input pressure?

3) Input pressure. My regulator has a gauge (which I am hoping is accurate), but what has me confused is what pressure to set it up at, and under what conditions. With NO water flow, the gauge used to read about 35psi, and when the rotary pump started up, the gauge would drop to about 20psi. Pump turned off, gauge would jump back up to 35psi. My test last night (that seems to mellow out the machine behavior), was I set the static pressure (no water flow) to 20psi, but when the pump kicks in, the pressure gauge shows a drop to about 12psi. What is the correct/most accurate way to set input pressure - flow, or no flow? Should the gauge read your desired input pressure under no flow conditions or under typical water flow conditions?

Grant

[HB]

...do the electronics typically emulate lever usage?

No, because they have no expansion chamber. Compare La Valentina (left) and the Levetta (right), which is similar to the Bricoletta lever versus volumetric model:



Correctly regulated, the pressure profiles should be very close, but not precisely the same. Below is a comparison of the Expobar Brewtus (E61 lever, vibe), Elektra A3 (proprietary group, rotary), and La Valentina (E61 solenoid, vibe):


From Pressure profiles, preinfusion and the forgiveness factor

I don't have a pressure profile that matches your machine, i.e., rotary pump, E61 solenoid. Because of the faster flow rate of a rotary pump, I would expect the gicleur in your machine will play a more vital role than one in a "true" E61 having an expansion chamber.

Does input pressure effect preinfusion, again..with a rotary pump and volumetric controls.

Technically, your machine doesn't have preinfusion in terms of the E61 patent. Like my La Valentina, your machine relies on what's generally referred to as "progressive preinfusion", i.e., a pressure increase attenuated by the gicleur.

What is the correct/most accurate way to set input pressure - flow, or no flow?

We're more concerned about the brew pressure, not the inlet line pressure, as long as the inlet pressure isn't too high and the flow rate isn't anemic. If your machine doesn't have a brew pressure gauge, measure with a pressure portafilter (either buy one or build your own). You'll get more accurate readings if you measure while there's a flow.

[malachi]

I am really hoping the problem the problem is NOT on the handle side of the PF. :oops:

We all hope that of ourselves...

[Grant]

We're more concerned about the brew pressure, not the inlet line pressure, as long as the inlet pressure isn't too high and the flow rate isn't anemic. If your machine doesn't have a brew pressure gauge, measure with a pressure portafilter (either buy one or build your own). You'll get more accurate readings if you measure while there's a flow.

I didn't know what to expect from water inlet pressure adjustments...this is the first time I have ever made any adjustments to it other than getting it in the ballpark - but the results are significant. Why? I have a handle mounted pressure gauge, and what I just don't understand is that previously (with the higher water line input pressure - 30PSI or higher (no flow)), and the brew pressure (adjusted on the pump) to 9BAR, the machine is very aggressive to the puck - lots of early blonding, channeling etc. - top of the puck after brew is rarely in good shape - lots of pitting and disruption.

Since reducing the the water line input pressure to 20PSI (no flow). and re-adjusting the pump back up to 9BAR, the machine is noticably more "gentle" to the puck. Far less disruption to the surface after brewing...and my last 14 shots (I am keeping a shot log at this point), seem to flow forever, are rich, dark, and incredible tasting. No early blonding since the change. I just don't undersand why or what is happening.

We all hope that of ourselves...

Happy that it seems at least some of the problem was on the machine side of the PF!

Grant

[eastpresso]

I don't have a pressure profile that matches your machine, i.e., rotary pump, E61 solenoid.

The rotary Bric does not have a solenoid

http://www.1st-line.com/machines/home_mod/fiorenzato/briccoletta_dc_lever.htm

(edit: in the lever version )

the vibe version does

http://www.fiorenzatocs.com/inglese/scheda_bricoletta.html

(edit: and so does the volumetric version, oops

http://www.1st-line.com/machines/home_mod/fiorenzato/briccoletta_dc_electronic.htm)

You would expect a quick pressure build up - so the profile is similar to the A3?

(edited)

[HB]

You would expect a quick pressure build up - so the profile is similar to the A3?

That would be my guess, since the A3 has a gicleur in the grouphead like the E61s. Additionally Grant's report about lowering the inlet pressure is consistent with my own from the Bench:

Static pressure reading after pressure regulator was put back in place (machine is cold)

So instead of the gauge over 4 bar (bad), it's now closer to 2 bar (good). Apparently the preinfusion design relies on low inlet pressure to function optimally. Moral of the story: Read the Owner's Manual and plan to buy a pressure regulator, period.