# Basket stated capacity vs actual - Help



## mharris (Feb 5, 2019)

Hi,

I've recently started using my espresso machine again - Gaggia Classic 2015 model (the drippy one). After a week of pretty bad shots (side-channelling etc), I realised that I was over filling the basket. 18g into an 18g VST basket, with a light tamp is too much. In fact its not even close - this is mashing the dry puck into the shower screen.

I need to go all the way down to 16g with a relatively firm tamp (until I can feel no more compaction) to get it to pass the 10p coin test, with only a slight indent.

This has got me wondering if this is usual, or if something is off about my setup or technique.

Perhaps this is a quirk of this machine, that the shower screen protrudes lower into the basket? It only has a 6.5mm filter gasket whereas other Classic models have 8.5mm. Maybe I'm not grinding fine enough..? Maybe my tamping technique is far too light..? Maybe I need to put 16g in and stop worrying..?

For reference it seems that I need to tamp so that the base of my Motta tamper (~10mm deep) is at or just below the rim of the basket to be in the right ball-park for headspace.

My last shot was Rave Signature Blend, ground on Eureka Mignon mk2, 16g in 34g out in 29 seconds.


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## El carajillo (Mar 16, 2013)

The gasket / seal for that model is 6.5 mm. Is it the correct VST basket for that model ?

I use an 18 gm basket in the older Classic without any problem, can even go to 19 gms.

You should be tamping quite firmly. What is the flow rate ? @ 16 gms X 2 = 32 gms - 25 - 30 secs


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## mharris (Feb 5, 2019)

El carajillo said:


> Is it the correct VST basket for that model ?


 Correct me if I am wrong, but I do not believe VST baskets are model specific..? I have the ridgeless 18g model number VST-183050r https://www.hasbean.co.uk/products/vst-filter-basket



El carajillo said:


> What is the flow rate ?


 Flow rate is detailed in the last line of my post above. 16g - 34g 29 seconds.


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## Mrboots2u (May 10, 2013)

mharris said:


> Hi,
> 
> I've recently started using my espresso machine again - Gaggia Classic 2015 model (the drippy one). After a week of pretty bad shots (side-channelling etc), I realised that I was over filling the basket. 18g into an 18g VST basket, with a light tamp is too much. In fact its not even close - this is mashing the dry puck into the shower screen.
> 
> ...


 Are grinding coarse ?

Are dosing to the nearest gram or the nearest 0.1g

It ok for the puck to expand and go abasing the shower screen after extraction ( coffee expands )

Put in 18g , add a 5p coins lock into group , take out again, is the 5 pl leaving a heavy imprint in the dry puck >


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## mharris (Feb 5, 2019)

Mrboots2u said:


> Are grinding coarse ?


 I really dont know (still a beginner). But my shot timings are in the expected range.



Mrboots2u said:


> Are dosing to the nearest gram or the nearest 0.1g


 Yes, nearest 0.1. I have scales accurate to 0.01 grams.



Mrboots2u said:


> Put in 18g , add a 5p coins lock into group , take out again, is the 5 pl leaving a heavy imprint in the dry puck >


 As per my original post.. 18g is contacting the shower screen, even before adding a coin.


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## Mrboots2u (May 10, 2013)

mharris said:


> I really dont know (still a beginner). But my shot timings are in the expected range.
> 
> Yes, nearest 0.1. I have scales accurate to 0.01 grams.
> 
> As per my original post.. 18g is contacting the shower screen, even before adding a coin.


 Whats the coffee


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## mharris (Feb 5, 2019)

Mrboots2u said:


> Whats the coffee


 Rave Signature Blend


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## Mrboots2u (May 10, 2013)

mharris said:


> Rave Signature Blend


 Ok not the darkest coffee in the world , is the basket seated in the pf ok? Is the shower screen seated correctly .

Perhaps a photo of he coffee ground, the coarser you grind the more of the basket it fills


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## Adrianmsmith (Dec 30, 2018)

is it possible you need to replace your gasket. as it wears it will effectively move the shower screen closer to the coffee, well the coffee closer to the shower screen actually!!

I use vst baskets on the Synchronika. 19g in the 18g basket. 21g in the 20g basket 24g in the 22g basket. I also use 26g in the 23g ecm basket.

ims shower screen and red silicone gasket. if i use the blue gasket i need another .2 to .3g approx

hope that helps


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## mharris (Feb 5, 2019)

Adrianmsmith said:


> is it possible you need to replace your gasket. as it wears it will effectively move the shower screen closer to the coffee, well the coffee closer to the shower screen actually!!


 This is what I'm thinking, and I will probably replace it for good measure anyway. A visual inspection suggests that it is in good condition. The machine hasn't been used a lot, so I'd be very surprised if the gasket has worn down enough to make any noticeable difference to the basket volume.

I have taken some photos, hopefully these may be helpful to diagnose. 16 and 17 grams, both with what I would consider light to medium tamp pressure. The 17g actually has some imprint from the shower screen on it.

I'd be interested to know what depth people generally have below the rim of their basket with a correctly tamped puck.


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