# Gaggia Evolution - just like the Classic, or not?



## James45 (Aug 24, 2021)

I got an Evolution second hand after reading about it online. "It's just like the Classic, but in a plastic housing!".

This was my first foray into espresso, and I thought it was worth the $200 gamble.

In short, after doing everything from playing with roasts and grind size to fully disassembling, cleaning and reassembling the machine, I can't get cafe-grade espresso out of this thing. Either it chokes or it flows too fast and underextracted. Some people have mentioned replacing the gaskets, but I'm under the impression that a gasket won't mean the difference between a terrible shot and a perfect one.

I don't want to invest more time and money into this, so if anyone has any tips on how to use this machine before I resell it and go back to my moka pot, I'd appreciate it. Can I adjust the pressure on this thing, somehow?


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## AndyDClements (Aug 29, 2016)

Quick search seems to indicate it's the same/ very similar internals if this is the model you have.

https://www.coffeeforums.co.uk/topic/21807-pid-on-a-gaggia-evolution/?do=embed

What grinder are you using? What beans and how fresh are they? How are you tamping etc? pretty much asking, describe the process of preparing the shot. then hopefully one of the people with the right knowledge can comment.


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## James45 (Aug 24, 2021)

Yup, that's the one I have.

Grinder: Porlex Grinder.

Beans: Locally roasted (purchased from the roastery), medium roast. I wait a few days before using the beans.

Prep: Turn on the machine, let it get hot. It turns off and on as what I imagine is the machine's rudimentary way of keeping a steady internal temperature. I measure out the coffee on a scale (I know exactly how much needs to go in this machine, it's not forgiving at all), tamp hard (30lbs approx), insert the portafilter and let it run right away.


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## Norvin (Sep 10, 2014)

Looking at the pictures it looks as if it is more like the Gaggia Coffee or the Gaggia Espresso rather than the Classic, i.e. it doesn't have the three way solenoid valve or adjustable OPV. The brew pressure is likely to be regulated by a non adjustable valve in the base of the group head.


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## James45 (Aug 24, 2021)

Norvin said:


> Looking at the pictures it looks as if it is more like the Gaggia Coffee or the Gaggia Espresso rather than the Classic, i.e. it doesn't have the three way solenoid valve or adjustable OPV. The brew pressure is likely to be regulated by a non adjustable valve in the base of the group head.


 All I found was a little threaded hexagonal nut that had a spring underneath. Is this the valve? I wasn't sure what it was when I was cleaning it, but it was fully tightened when I removed it, so I tightened it fully when I put it back in.

I'm just trying to figure out if it's worth cutting my losses on this machine. I think that the Classic and the Silvia are recommended as "base" machines for a reason, and even then some people say they aren't that great.


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## Norvin (Sep 10, 2014)

There should be a rubber valve in there on the end of the spring. The head is machined differently from the 'better' machines so can't be upgraded by fitting parts.


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## James45 (Aug 24, 2021)

Yeah, the black bit was there. I put everything back as it was.


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## GranGaggia_old_version (10 mo ago)

Hi, I had a look at the schematic on mr bean2cup. The evolution has part 31 "GAGGIA CAREZZA SAFETY VALVE (OPV). This is sometimes referred to as the 'hidden' opv. Its located on the brass fitting on the outflow of the pump. It returns excess pressurised water to the tank. The valve in the group head is only their to allow pressure to build up for the steam wand. increasing tension of the group head spring is a bad idea as it means steam pressures will reach dangerous levels. So any way, the hidden opv is covered by a black rubber hose connector . take it off and youll see a little flat head screw to adjust over presure. left loosy righty tighty. turn left to loosen spring tension and decrease brew pressure. I attached a bicycle pump with a pressure gauge under the steam wand and then placed some books under the bicycle pump to wedge it in place as the pressure pops it off otherwise. you can check you ajustment this way. Remember to only test the machine pressure when the machine is fully assembeled back to normal. Otherwise youll electrocute yourself. Also allways unplug when opening it up. I electrocuted myself twice attaching a thermo probe to the thermoblock of my gaggia gran by leaving it pluged in despite it 'looking all good'. I am interested to know if this helps. As far as I know, ever gaggia that doesnt have a big OVP, still needs a ovp, so has the hidden ovp. The hidden one might even be better as it recirculates redundent cold water directly at the pump. Just some ideas. Let me know. Once people learn of the hidden ovp the prices will rise a little on ebay i think. Havent seen a youtube video on it yet.  Gaggia Cubika to the moooon!


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## Rincewind (Aug 25, 2020)

GranGaggia_old_version said:


> Hi, I had a look at the schematic on mr bean2cup. The evolution has part 32 "GAGGIA CAREZZA SAFETY VALVE (OPV"...


Sorry but i can't see part 32 on the picture shown in your post.


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## Bhodgson (11 mo ago)

The group head is different from the classic. Having plastic internals. these can get damaged.
A new group gasket can 100% improve a shot. A weak seal causes variations in pressure.
id wait for a real classic to come up, if I were you.


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