# Help required with gaggia classic



## kraken (Mar 21, 2015)

Hi. I have a problem. I can't make great coffee :-(.

Here's my setup

- Gaggia Classic. At least 5 years old. Recently descaled. Backflushed.

- Gaggia standard wand replaced with v1/v2 Rancilio Silvia wand.

- Kitchaid burr grinder. Less than 1 year old.

So, the grinder can't grind coffee fine enough for espresso. I've adjusted the hell out of it and still no joy. When adjusted to the extreme it can just about grind fine enough, but the motor is straining. The burrs have wear marks on certain areas, probably from my over adjustment.

Even with slightly too coarse a grind, the gaggia can't pump a double shot in 25-30 secs. If I tamp the 'normal' amount then there is next to no flow at all. Just drips. If I tamp really lightly - by lightly I mean hardly anymore than the weight of the tamper itself - then a double shot might take 1 minute. (Based on 18g coffee of 1 month old beans and 60ml final shot volume).

So, I'm thinking that the gaggia pump is faulty. Not enough pressure. But, when I use fine pre-ground Lavazza coffee, it flows through fine! Even if I tamp quite hard (haven't managed to check the 30lb, but it's probably that sort of order).

What's happening? Is there something going on with the coarser freshly ground that I'm missing? I did once hear that coarse grinds can float to the top of portafilter and block the flow. Is this possible?

Thanks for your help in advance.


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## Mmiah (Feb 13, 2015)

Are you using a pressurised basket?


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## kraken (Mar 21, 2015)

No. I'm using the standard multihole double shot basket.


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## The Systemic Kid (Nov 23, 2012)

The clue is in the....



> But, when I use fine pre-ground Lavazza coffee, it flows through fine! Even if I tamp quite hard (haven't managed to check the 30lb, but it's probably that sort of order).


Your grinder is not producing consistent grind - burrs sound knackered. Fraid you need to get a better grinder.


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## Scotford (Apr 24, 2014)

I have a funny feeling that you're actually grinding way too fine.


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## kraken (Mar 21, 2015)

I'm certain the grind is not too fine. I've recently been on a home barista course at Extract Coffee Roasters in Bristol. I took a sample of my grinds and they said it's too coarse. It feels and looks too course.

Interesting point about the consistency of grind. How might this affect things?


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## The Systemic Kid (Nov 23, 2012)

Pressurised water going through the puck will look for path of least resistance. If your puck is made up from a wide range of particle size - tiny (fines) to large (boulders) the water won't flow evenly through th puck and you won't get decent extractions.


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## m4lcs67 (Mar 16, 2014)

Agree with the above comments. Looks like a new grinder or a major overhaul of your current one. If you can afford a new one you would be well advised to though.


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## kraken (Mar 21, 2015)

How would a mixture of grind sizes choke my machine? I can understand that it might cause uneven flow and poor extraction, but can't see that it would choke the flow.

Too be honest I don't think I have a problem with inconsistent grinds. Or at least it's not noticeable to the eye or feel.

The comment ref the kitchenaid grinder 'If you can afford a new one you would be well advised to though.'. Is this because the grinder is regarded as being a bit rubbish?? Honest comments welcome. It was a present. With subsequent research it's not a grinder I would have bought myself!!


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## The Systemic Kid (Nov 23, 2012)

Fines in the puck migrate towards the bottom during extraction and create resistance to the water pressure from the machine's pump. If there are too many fines, the flow can get blocked.


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## MWJB (Feb 28, 2012)

Try sieving out the larger particles in your grind (kitchen sieve/tea strainer), then load the PF with 18g again & see what difference that makes?

All burr grinders make a range of grind sizes (distribution), some just have narrower distribution than others, start by culling the larger particles, whilst you save for a new grinder.

How much weight of shot are you getting out?


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## kraken (Mar 21, 2015)

In response to systemickid -

Ok, that's a possibility. I don't think I'd know easily if the fines were present.

If this is the case, then surely the flow would start off ok and the filter would gradually get blocked during the extraction. This isn't the case. There is NO flow initially. Only after some time do drips of coffee start flowing.


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## MWJB (Feb 28, 2012)

kraken said:


> In response to systemickid -
> 
> Ok, that's a possibility. I don't think I'd know easily if the fines were present.
> 
> If this is the case, then surely the flow would start off ok and the filter would gradually get blocked during the extraction. This isn't the case. There is NO flow initially. Only after some time do drips of coffee start flowing.


You have fines...everyone does.

You're saying your grind is coarse to the feel & to look at, make it less coarse, with fewer large boulders (sieve out what you can) & see what happens (in terms of seconds & g of shot weight produced).

You don't seem to be able to make it considerably finer, to make the flow quicker would mean going coarser still...which is a possibility but will probably net a low extraction.


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## MrShades (Jul 29, 2009)

Sounds like a grinder issue (yes, you're right, it's a pretty crap grinder) - possibly combined with a dosing issue too... but who knows at the moment.

So - first key question: Are you sure the dose is 18g? It's around the sweet spot for a double basket on a Classic - so should be fine.

I'm with Scotford - I think you're grinding too fine - but possibly also under dosing. My initial guess is "Loosen the grind and dose more" - but let's see...


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## Scotford (Apr 24, 2014)

OP, have you actually tried loosening the grind and seeing if that makes a difference?


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## jamster (Feb 6, 2014)

I used a hario hand grinder for a while with my Gaggia. It was a pain to get 'dialed in' Nd took a long time to grind 18g at espresso fineness, but at only £20 or so it was a good investment to help get a feel for different fineness and I can still use it now for other brew methods. Perhaps a useful tool to help you diagnose where the problem is?


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## No big name! (Oct 25, 2012)

Just to take one on the variables out of the equation; have you tried measuring the flow without portafilter and/or coffee?

I fixed my sister's Classic recently and the flow was weak even without portafilter in place.

I would rule that out before you move onto grind adjustment

NBN


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## Wando64 (Feb 28, 2011)

I am with NoBigName above.

Just because you have descaled and backflushed it doesn't mean that your machine is actually clean.

If there is a blockage it might not be dislodged by descaling and backflushing alone.

All other suggestions are also valid, but they all assume you have a clean machine with an appropriate flow of water.


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## kraken (Mar 21, 2015)

To try and answer all questions and my own comments since my last post -

- I weigh out my 18g, so there's no problem with the dose.

- The only way I get a double shot that extracts in 25-30 seconds and is 60ml in volume is with a coarse grind. By coarse, I mean the sort of grind you'd put in a clever dripper. This of course results in poor extraction.

- There's no way I'm grinding too fine. Compared to Lavazza pre-ground I'm more coarse. Possibly due to inconsistent grinding I've got too many fines, which is causing the choking issue.

- I like the idea of getting a hand grinder to play around with different grinds. I'm also able to borrow a gaggia mdf, which I know grinds well, so I can use that to diagnose the problem. Or ... confuse things even more!!

- I'm pretty certain the flow without the filter is fine. As I said in my original post, the flow is fine using pre-ground Lavazza.

My plan now is to try the gaggia with some MDF ground coffee. If that works then clearly it's the Kitchenaid grinder. The grinder is within the 2 years warranty, so I'll try my luck in getting a full refund from Kitchenaid!!


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## Scotford (Apr 24, 2014)

You're trying to get too much out of an 18g dose. At work we use 18 into 34g. That is a double shot as standard.


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## Mrboots2u (May 10, 2013)

Scotford said:


> You're trying to get too much out of an 18g dose. At work we use 18 into 34g. That is a double shot as standard.


Bit more info behind the thinking in that please ta.

Op is limited by his grinder somewhat..


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## Scotford (Apr 24, 2014)

Mrboots2u said:


> Bit more info behind the thinking in that pleaee . ta


60ml out of 18g? That is enough info there, ta.

18 into 34 as a double? Its a widely accepted dose for a double shot. We use 34 as per our recipe as its where we find maximum sweetness comes through without any bitterness and the nuttiness of the Mexico in it really shines.


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## Mrboots2u (May 10, 2013)

Scotford said:


> 60ml out of 18g? That is enough info there, ta.
> 
> 18 into 34 as a double? Its a widely accepted dose for a double shot. We use 34 as per our recipe as its where we find maximum sweetness comes through without any bitterness and the nuttiness of the Mexico in it really shines.


Sorry thought op was trying to get 36 g out not 60 ml...you are of course correct, 60 ml is too much







. Now get onto free pour Friday and diagnose my wiggle issues


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## marcuswar (Aug 19, 2013)

Forget all the talk about singles and doubles as it's just confusing, just think about it purley in terms of ratios. i.e 1:2 = 18g in -> 36g out , or 1:6 = 18g in -> 29g out


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## Mrboots2u (May 10, 2013)

marcuswar said:


> Forget all the talk about singles and doubles as it's just confusing, just think about it purley in terms of ratios. i.e 1:2 = 18g in -> 36g out , or 1:6 = 18g in -> 29g out


Plus one on above

Go here

http://coffeeforums.co.uk/showthread.php?t=22879

Read , ask questions


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## kraken (Mar 21, 2015)

Ok, I thought 60ml was perhaps on the long side. Presumably the 34g is a 34ml final volume?

My machine would get no where near 34ml unless I had the much coarser grind.


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## kraken (Mar 21, 2015)

Mrboots2u said:


> Plus one on above
> 
> Go here
> 
> ...


Ok, have now read this. All is clear. Ta.


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## kraken (Mar 21, 2015)

Just an update on this one.

I've bought some freshly ground coffee from a local cafe. Fresh beans. I asked for espresso grind and it certainly looks and feels exactly how I understand espresso grind to be.

18g in my gaggia worked a treat. Tamped to a reasonable level (can't check the 30lb, but it feels about right). 27 second extraction gives me about 34g of shot, plus/minus a few grams depending on my tamp. Nice crema.

So, I can only conclude, as has been previously suggested, that my Kitchenaid grinder is giving me an inconsistent grind which on the face of it looks/feels too coarse, but actually has many fines that are choking my coffee machine.

In parallel, I'm getting used to my new ranchilio wand and starting to make some half decent microfoam. All in all, things are looking up!!

Thanks to everyone for all the posts. Now just need to get a new grinder!!


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