Requesting some troubleshooting advice for La Pavoni Europiccola - Page 4

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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meastway
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#31: Post by meastway »

This is starting to run off topic but...

Agree. Ideal boiler temp/pressure is dependent on group temp. There's a dance between these two to achieve consistency. It is easier to make changes to boiler temp than group temp, once you are in the ballpark.
For group temp adjustments - flush into a cup to bring temps up, method of your choice to bring temps down (I have a piece of Al I machined down to fit in a basket that just kisses the shower screen when locked in. That sits in a spare portafilter in cold water during a session. I lock this in for a couple minutes after each shot to regulate group temp).

For reference I have a dual switch europiccola. I have a pressure gauge on the top of my sight glass (from OE) and a thermocouple probe stuck to the group bell. My taste buds tell me they like this recipe - I aim for about 185deg on the bell and 9.5-10psi(0.65-0.69 bar) on the gauge to start shots. My bell readings during the shot usually read 194-199 (depending on the coffee). Your numbers may(will) vary. You could start with higher boiler temp and lower group temp but the bigger the difference the harder it is to nail the desired brew temp.
When I'm ready to steam I just kick it to full power and wait for 1 bar or so in the boiler.

In my opinion a boiler pressure gauge is basically a necessity. And if you want consistency, some way to check the temp of the group.
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avh (original poster)
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#32: Post by avh (original poster) »

Resurrecting my old thread ...

After a long time of not using the Pavoni due to various circumstances I recently tried pulling a shot again while coarsening the grind a bit.
I seem to get better shots with a slightly coarser grind and similar tamp, so that works! Now the next step is to optimize the rest of the process.


By the way: is there any consensus about preferred particle size for ground coffee for each brewing method? The reason I'm asking this is because I have access to laser diffraction equipment to determine particle size distribution (Malvern Mastersizer) and I would like to 'calibrate' my grinder to settings ideal for e.g. espresso, drip, french press et cetera.

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RioCruz
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#33: Post by RioCruz »

avh wrote:By the way: is there any consensus about preferred particle size for ground coffee for each brewing method?
Yes. Whichever particle size gives you the taste you like best. That's really all that matters as far as I'm concerned.

I recently changed the grind setting on my HG-1 to a finer grind for my Aeropress. The result was a heavier, more robust flavor...but the cup lacked the layered nuances of taste I get from a coarser grind. I tried out the new setting for a few days and and actually liked it, but then went back to the old setting because I preferred the nuances of flavor I got at that setting.

Just experiment around and find the taste and flavor you like best...
"Nobody loves your coffee more than you do."
~James Freeman, Blue Bottle

avh (original poster)
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#34: Post by avh (original poster) »

That seems reasonable :D maybe my approach is a too analytical.

I will however do some experiments anyway, I'm too curious to see how homogeneously the grinder can grind the particles.

avh (original poster)
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#35: Post by avh (original poster) »

As mentioned I performed some measurements of my Compak K3 for those who are interested!

I made measurements at setting a around 39, 42 and 52; corresponding to positions 1, 2 and 4 on the photograph below:


Measurement results:


I was a bit surprised at the big second peak, even at a espresso-range setting at 39. Anyone care to give their thoughts?

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drgary
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#36: Post by drgary »

We're far from the analog world of manual levers, but since you're asking, It's well known that espresso grinders generally produce bimodal distributions of particle sizes.

Titan Grinder Project: Particle size distributions of ground coffee

Why are conical burrs inherently bimodal?
Gary
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What I WOULD do for a good cup of coffee!

avh (original poster)
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#37: Post by avh (original poster) »

drgary wrote:We're far from the analog world of manual levers
True; it might've been smarter to have started a new thread or to have piggybacked onto a relevant thread.
drgary wrote:but since you're asking, It's well known that espresso grinders generally produce bimodal distributions of particle sizes.

Titan Grinder Project: Particle size distributions of ground coffee
That's quite interesting. I noticed that the thread you mentioned calculates the particle size not only as volume distribution, but also as surface area and number density. For completeness sake I did the same thing and it seems that my results are quite similarly shaped.

Number density:

Surface area:

Overlay of all three:

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drgary
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#38: Post by drgary »

RioCruz wrote:Yes. Whichever particle size gives you the taste you like best. That's really all that matters as far as I'm concerned.

I recently changed the grind setting on my HG-1 to a finer grind for my Aeropress. The result was a heavier, more robust flavor...but the cup lacked the layered nuances of taste I get from a coarser grind. I tried out the new setting for a few days and and actually liked it, but then went back to the old setting because I preferred the nuances of flavor I got at that setting.

Just experiment around and find the taste and flavor you like best...
Since they all go bimodal, that's a given. And you can measure these things to death. But I don't think anything is as refined a measurement as your taste buds. I agree with what Rio wrote above.
Gary
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What I WOULD do for a good cup of coffee!

OldNuc
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#39: Post by OldNuc »

Taste buds are unique and the total number of taste buds equals the total number of different opinions. If you like the taste then that is correct for you.

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