Londinium Compact. - Page 26

A haven dedicated to manual espresso machine aficionados.
Cuprajake

#251: Post by Cuprajake »

cheers for the reply, i now understand the theory behind it, not sure how much temp you'd loose lol its not like its a mile run of pipe haha

mathof

#252: Post by mathof replying to Cuprajake »

One point occurred to me later. The additional pressure for light beans would help the PI brew water to penetrate the more compact pucks formed by the finer grinds needed to assist extraction.

LObin

#253: Post by LObin replying to mathof »

Indeed. Another positive effect of higher PI with light roast is the quicker the puck is fully saturated, the more stable the extraction temperature will be.
LMWDP #592

Jonk

#254: Post by Jonk »

mathof wrote:The additional pressure for light beans would help the PI brew water to penetrate the more compact pucks formed by the finer grinds needed to assist extraction.
Is this really the case though? When the grounds are not overly fine - sure - but with really fine grinds I'm under the impression that lower pressure is more helpful.

Other than that, I haven't experienced much difference from say <1 bar to 3 bar PI pressure either as far as flavor goes. I'm sure the Vectis will do fine coupled with a suitable grinder.

LObin

#255: Post by LObin replying to Jonk »

My experience is different. When playing with the line preinfusion on my ex-Bezzera B3000al, I felt like it was easy to pick the difference with low line preinfusion (1-1.5 bar) and higher line preinfusion (2-3.5 bar).
For some coffees, It felt like some specific notes were revealed under higher preinfusion while being more muted or absent with low PI. Definitely not a universal rule but it was definitely great to experience with PI and eventually, dial-in and pull better shots.
When I made the switch to my now ex-L1, I was never able to fully recreate the depth of those pulls with lighter roasts and higher PI. Manipulating the lever did change the profile but I was never as consistent and as successful as I was with the Bezzera.
Larger shot volume is also an advantage of high PI because of the dispersion of the trapped air.

Selling the Bezzera for a Londinium 1, I did switch from a HX to a dipper (well... Open loop thermosyphon actually) so differences are to be expected, just like one should when considering getting either the Compressa or the Vectis.
LMWDP #592

mathof

#256: Post by mathof »

LObin wrote: When I made the switch to my now ex-L1, I was never able to fully recreate the depth of those pulls with lighter roasts and higher PI. Manipulating the lever did change the profile but I was never as consistent and as successful as I was with the Bezzera.
Larger shot volume is also an advantage of high PI because of the dispersion of the trapped air.
You list your current machine as "Custom LP Pro's". I'm curious to know what that means, and how you are getting on with whatever you are using now.

EDIT: I just saw a video of you pulling a shot on a La Pavoni. Now I see what LP Pro's stands for. I confused it with L-P, meaning Londinium professional. Sorry for the confusion.

LObin

#257: Post by LObin replying to mathof »

I'm sure I would get along just fine with an old Londinium P but the cost of a cm2 of counter space has gone up dramatically. At least, that's what my wife tells me...

And I do really enjoy the profiling abilities of a manual lever :)
Cheers!
LMWDP #592

iyayy

#258: Post by iyayy »

hi.
i've been reading this post since i'm interested in small spring lever.
im wondering does any spring lever has gauge to show pressure at group head? i hope to have visible control.
with my bdb i do manual pi to ensure group head fills properly and release atfter reaching 2 bar to brew up to 9.

that aside, reading the posts here i started try reaching higher pi pressure before release.
2.5, 3, and 4 bar.

im suprised that difference between 2.0 and 2.5 was immediately obvious.
2.0 is relatively muddy and thick, actually still complex and nice.
2.5 is extremely vibrant on acidity and clarity, doesnt work well with milk too, acid messes the taste.
and 3 seems to do a better balance, but im not a very exciting shot.
4 needs notable grind change since liquid starts flowing during pi alrdy. i dont have a good comparison case as shots flows too fast. the shot is my best preference so far. sweet and floral on latte, especially after cools.

i havent test these with dark roasts, but difference on medium roast is much less pronounced compared to light.

i do have problems since the flat pressure turns the last yield bitter very fast, and hopes lever can help solve this. based on puck color i feel i still waste some last gram on it.
reading here i feel the 2 step pi seems very convincing, but i hope to have a gauge to be consistent.

mathof

#259: Post by mathof »

LObin wrote:I'm sure I would get along just fine with an old Londinium P but the value of a cm2 of counter space has gone up dramatically. At least, that's what my wife tells me...

And I do really enjoy the profiling abilities of a manual lever :)
Cheers!
Actually, I still have a pre-millennium LP Europiccola which I bought new in 1999 and used daily until 2014 when I bought my L1. Mine too is much modified (custom-made base), anti-vac/safety valve), manometer, etc. I used the it recently while the L1 was down, and it made VERY good espresso. (Steaming was relatively weak, though.)

LObin

#260: Post by LObin replying to mathof »

They are truly wonderful machines :)
There's a very simple pstat bypass mod that only requires a dual switch and a little rewiring. I now steam at 1.5 bar. Send me a DM if you ever want to try it!
LMWDP #592