# Gaggia Classic advice



## gihe (Jul 22, 2010)

Hello. I recently purchased a second-hand Gaggia Classic from *well-known auction site*. It's in good nick and only had light use.

So far, I've managed to make a half-decent cup by tamping the coffee lightly. However, several sites have recommended 30-40lbs of pressure to tamp the grind - and when I try that, the water simply doesn't come through the portafilter. The machine just sits there chuntering away and nothing happens. I've checked the showerhead and it's clear.

What could be wrong? How can I verify that the pump pressure is up to spec?

I'm using standard Illy espresso pre-ground.

Any advice would be appreciated.

Thanks


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## Glenn (Jun 14, 2008)

Try varying the amount of coffee you are using. Try 14-15g of coffee and a firm tamp and see if that makes a difference.

It could be that you are putting too much coffee in the basket

The 30-40lbs can largely be ignored as the tamp pressure varies with the grind.

If you can flip the portafilter upside down without the grounds falling out then you are in the right ballpark.

When you grind and tamp you have 2 variables to control and can then start to see different extraction results.


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## FurryCup (Jun 10, 2010)

Hi, how are you measuring your tamping pressure? I have a Espro tamper which measures the tamp pressure to 30lb. The first time I used it I was amazed how light 30lb actually is! I had been tamping much heavier than 30lb (I would forget 40lb). You can measure 30lb of pressure by tamping on a set of bathroom scales. I would take a guess and say you are tamping much harder than the 30lb you are aiming for. As you cannot adjust your grind just go for a 25-29 sec pour time for a double espresso and don't concentrate too much on tamping at 30lb until you are able to adjust your grind with the new grinder that will soon be on your shopping list!


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## gihe (Jul 22, 2010)

Hi. After a bit of experimentation, here's what I've found.

I was originally using about 14-15g of coffee and tamping very lightly (about 1 or 2lb of pressure). Even at this low pressure, the coffee doesn't fall out of the portafilter when inverted. The resulting brew is strong with a reasonable crema but bitter.

I then tried a firmer tamp (using bathroom scales to get to around 18lbs) and the same amount of coffee. This time the brew was smoother and less strong - more like an Americano flavour-wise - and with less crema.

Finally I tried a 30lb tamp (or rather I managed about 23lbs - just impossible to go any higher with that pre-suppled plastic tamper) and the brew was slightly smoother again but with even less crema - just a thin layer on top, which disappeared a couple of minutes later.

Point to note - as the pressure increased, there was more water standing on top of the puck after the shot.

I think the times when the machine didn't do anything was when I had over-filled and levelled off (so, yes, too much coffee).

So - what can I infer from all this? Is it the pump or something else?


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## gihe (Jul 22, 2010)

Just to add - I did all the tests with exactly 15g of coffee


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## Glenn (Jun 14, 2008)

Where are you based? If you are anywhere near where I will be I'd be happy to pop in and take a look (and share a coffee or two)


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## gihe (Jul 22, 2010)

Glenn said:


> Where are you based? If you are anywhere near where I will be I'd be happy to pop in and take a look (and share a coffee or two)


A kind offer - I'm in Coventry.


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## Glenn (Jun 14, 2008)

If you're still stuck next Thursday then let me know. Should be zipping by around about 7pm if thats not too late.


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## RisingPower (Dec 27, 2009)

gihe said:


> I'm using standard Illy espresso pre-ground.


There's your problem.


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## RisingPower (Dec 27, 2009)

I'd also recommend throwing away the plastic tamper and replace it with even the cheap one from happydonkey. You won't get any half decent result out of that plastic tamper.

Firstly, you'll note, there's a very large gap around the outside of it, secondly, it'll flex, thirdly, it's not even remotely flat.


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## gihe (Jul 22, 2010)

RisingPower said:


> There's your problem.


You're right about the plastic tamper - it's pretty useless. But can you elaborate on your comment about Illy pre-ground being the problem?


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## RisingPower (Dec 27, 2009)

gihe said:


> You're right about the plastic tamper - it's pretty useless. But can you elaborate on your comment about Illy pre-ground being the problem?


Well, it's stale, it's probably the wrong coarseness and it doesn't taste brilliant to start off with. You can forget getting anything which approaches espresso out of it.


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