My Take On Cremina - From Start To...

[flynnaus]

What beans have you been using Barry? I have pretty much restricted my use of the Cremina to single origins at their peak and then resorting to my Profitec for the other days.Some blends have shone - one I can remember was 2/3 Eth Harrar Longberry, 1/3 Costa Rican, surprising in that I wasn't expecting much from that blend.

To heat my grouphead, I wait until the boiler comes up to temp and then half fill each of two cups (typically Duralex 250ml) then prepare my shots. By then, the head has reached 75deg.
I also have a warmed 70mL cup on hand as one pull of the lever will usually dispense more than a shot's worth of espresso. I pull the rest into the espresso cup to relieve pressure enough to allow me to carefully remove the portafilter (and I drink it).

[Barry O'Speedwagon]

The problem, for me, is bringing the group up to temperature for my first shot (2 or 3 full pumps and, depending on ambient temperature, up to 6 half pumps). So, wouldn't want to go any lower than 1.0 BAR.

Ps don't think I'd be game to try to bring it up to 8.6ish BAR. I'm guessing there would be no shortage of steam at that pressure.
Besides, my gauge only goes up to 2.5 BAR.

Very true. My manometer has a 10 times converter on it

I probably will push it up a tiny bit, but have been happy with the results thus far...the taste is definitely closer to what I want. Will spend the rest of the week working on 1 other variable at a time. The change in pressure has certainly reduced the temp surfing required. Other than locking in a cold portafilter after washing it, by the time I was ready for my second copy the group was back at 75 degrees.

[OCD]

...Have now adjusted up again to a range of about 7.4-8.6ish...

The problem, for me, is bringing the group up to temperature for my first shot (2 or 3 full pumps and, depending on ambient temperature, up to 6 half pumps). So, wouldn't want to go any lower than 1.0 BAR.

Ps don't think I'd be game to try to bring it up to 8.6ish BAR. I'm guessing there would be no shortage of steam at that pressure.
Besides, my gauge only goes up to 2.5 BAR.

[Barry O'Speedwagon]

With the possible exception of the foreign power plug thingy they shipped the machine with, I can't imagine Olympia Express getting it so wrong that the dealers couldn't, in good conscience, allow the machines out of their showrooms without first pulling them apart to put things right.

Ps if you decide to go ahead and lower your pressurestat settings, let us know how it works out for you.

OK. So I've opened her up and had a play with the pressurestat. It is a Mater pressurestat inside. My initial adjustment down went a little too far. Maxing out at 8.0 meant that the boiler would reach 6.8 bar before switching on again (and not much steam if you start stretching milk at that point). This morning I bumped up to he pressure to a range of 7.0-8.2ish. Made a very smooth ristretto, but the coffee was a little 'cool'. Have now adjusted up again to a range of about 7.4-8.6ish. Made another nice ristretto, a little warmer in the cup (and is still tasting nice after cooling to room temp). Going to leave the pressure as is for some time now. Will note any changes in the need for surfing to drop the group temp after pulling a shot.

[Caffeinator]

Does this refer to a machine with the piston pressure gauge mod plus a naked portafilter? Or something else?

This one: https://www.naked-portafilter.com/pr...a-2011-recent/

[Barry O'Speedwagon]

The Swiss are renown for getting things perfect.

Except their cheese. Still full of holes.

Had an opportunity to play with a Cremina recently with the naked-portafilter profiling upgrade and it was a gorgeous thing.

Does this refer to a machine with the piston pressure gauge mod plus a naked portafilter? Or something else?

[Caffeinator]

The Swiss are renown for getting things perfect. They do it with the Cremina too and it's rare (pretty much unheard of) that you'd do more than fit a plug (they sadly don't produce a machine with an Oz/NZ power lead).

Minor adjustments to pressurestat? Most I have seen have a Mater fitted and it's more likely variation in these post manufacture than much else. I wouldn't worry too much about them, but if you're in, adjust away. It certainly won't do any harm and there's plenty of steam to be had at 0.75Bar.

These things produce exceptional coffee in the right hands and they really are little jewels. There are so many pretty faces in espresso gear that are shocking once you are inside. When you open a Cremina or even moreso a Maximatic, you see why they are priced as they are. The manufacturers go well above and beyond.

Had an opportunity to play with a Cremina recently with the naked-portafilter profiling upgrade and it was a gorgeous thing.

[Barry O'Speedwagon]

With the possible exception of the foreign power plug thingy they shipped the machine with, I can't imagine Olympia Express getting it so wrong that the dealers couldn't, in good conscience, allow the machines out of their showrooms without first pulling them apart to put things right.

Ps if you decide to go ahead and lower your pressurestat settings, let us know how it works out for you.

Will definitely let you know when I do have a go. Looks easy enough to open up. Just switched bags of beans so I'll stick with my current set up til at least the weekend.

[OCD]

...I guess it might depend on what the retailer does in the bench test (assuming such an event occurs).

With the possible exception of the foreign power plug thingy they shipped the machine with, I can't imagine Olympia Express getting it so wrong that the dealers couldn't, in good conscience, allow the machines out of their showrooms without first pulling them apart to put things right.

Ps if you decide to go ahead and lower your pressurestat settings, let us know how it works out for you.

[Barry O'Speedwagon]

I knew my Cremina was a precision instrument but to read that it's set at 92.2°C brewing temperature - unbelievable. And here I was, wasting my time with all that unnecessary temperature surfing.
Could someone elaborate as to the right time to lower the lever so as to achieve the stated 9 BAR extraction pressure? I don't think I'm getting anywhere near 9 BAR. My timing is obviously way off.
Also, my Cremina was never set to between .7 and .8 BAR.
I'm starting to think I've been lumbered with a counterfeit Cremina, albeit a damned good copy. Most likely South Korean.

Ps and the clincher. It's not even black. More of a dark metal flake grey.

Seem to be quite a few people on HB who received theirs with the pstat hovering in the range of your machine and mine. And quite a few who received their machine with the pstat in the 0.7-0.8 range. I guess it might depend on what the retailer does in the bench test (assuming such an event occurs).

[OCD]

..."The default pressure is adjusted to between 0.7 and 0.8 bars and the brewing temperature to 92.2 deg C. The Cremina leaves it to the skill of the barista to find the required nine bar pressure onto the portafilter by lowering the lever at just the right time...

I knew my Cremina was a precision instrument but to read that it's set at 92.2°C brewing temperature - unbelievable. And here I was, wasting my time with all that unnecessary temperature surfing.
Could someone elaborate as to the right time to lower the lever so as to achieve the stated 9 BAR extraction pressure? I don't think I'm getting anywhere near 9 BAR. My timing is obviously way off.
Also, my Cremina was never set to between .7 and .8 BAR.
I'm starting to think I've been lumbered with a counterfeit Cremina, albeit a damned good copy. Most likely South Korean.

Ps and the clincher. It's not even black. More of a dark metal flake grey.

[Barry O'Speedwagon]

This post deserves a response andcould be worthy of its own thread. I haven't got into boiler temperature changes other than the trade off betwen shot quality vs steam volume. I would guess there would be some variation in shot quality over the 3° c range you mention.
Other factors would affect shot quality afforded by extraction pressure would be length of preinfusion, lever pulling technique, grind quality, filter basket quality,
The question worth considering, especially with a machine of the quality of the Cremina is whether there is a need to change the boiler pressure at all (from default) given the other factors available. I guess the answer is why not if it provides significant improvement to your shots but what you could achieve the same improvement via other means.

I guess part of the answer is that Cremina's universal advertising blurb for their own product, states the following (this is from Coffee Parts, but is extracted from Olympia's press pack elsewhere): "The default pressure is adjusted to between 0.7 and 0.8 bars and the brewing temperature to 92.2 deg C. The Cremina leaves it to the skill of the barista to find the required nine bar pressure onto the portafilter by lowering the lever at just the right time."

https://www.coffeeparts.com.au/olympia-cremina-black

I still haven't adjusted mine yet, but will likely give it a go soon.

[flynnaus]

The temperature difference between .8 BAR @ 117.14°C and 1 BAR @ 120.42°C is only 3.28°C.
Given that the ideal extraction temperature (at the puck) is somewhere around 92°C, I wonder how critical a boiler temperature variation of 3.28°C can be in practice.
Surfing the group head temperature, so that the water arrives at the puck at the desired 92°C (give or take) should mitigate any temperature variation in the boiler.
On the other hand: higher boiler pressure = more steam.

Ps boiler pressure has no bearing on extraction pressure - only on pre-infusion pressure.

Ps2 there will, of course, be factors I haven't taken into account. Your thoughts? Criticisms?

This post deserves a response andcould be worthy of its own thread. I haven't got into boiler temperature changes other than the trade off betwen shot quality vs steam volume. I would guess there would be some variation in shot quality over the 3° c range you mention.
Other factors would affect shot quality afforded by extraction pressure would be length of preinfusion, lever pulling technique, grind quality, filter basket quality,
The question worth considering, especially with a machine of the quality of the Cremina is whether there is a need to change the boiler pressure at all (from default) given the other factors available. I guess the answer is why not if it provides significant improvement to your shots but what you could achieve the same improvement via other means.

[OCD]

.8 BAR vs 1 BAR Musing.

The temperature difference between .8 BAR @ 117.14°C and 1 BAR @ 120.42°C is only 3.28°C.
Given that the ideal extraction temperature (at the puck) is somewhere around 92°C, I wonder how critical a boiler temperature variation of 3.28°C can be in practice.
Surfing the group head temperature, so that the water arrives at the puck at the desired 92°C (give or take) should mitigate any temperature variation in the boiler.
On the other hand: higher boiler pressure = more steam.

Ps boiler pressure has no bearing on extraction pressure - only on pre-infusion pressure.

Ps2 there will, of course, be factors I haven't taken into account. Your thoughts? Criticisms?

[flynnaus]

See this thread to adjust the pstat
https://www.home-barista.com/levers/...nt-t44781.html

I should correct this. I believe your Cremina would not have the old mechanical pstat as portrayed in the video. Rather, I think they use a Sirai pstat or similar and adjustment would likely be by means of a screw on top of the pstat.