# Uneven flow on a twin-spout portafilter



## RoloD (Oct 13, 2010)

Using the twin-spout portafilter on my Gaggia Classic, coffee always seems to flow faster out of the left side, making it hard to do two equal single espressos at once.

Anyone else suffer from this?

Solutions?

Thanks


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## Fran (Dec 27, 2010)

Despite my limited experience, I would imagine that this was something to do with tamping. Perhaps uneven tamping, or uneven distribution of coffee prior to tamping, or perhaps even the wrong sized tamper. My classic came with a cheap plastic tamper which doesn't fit the basket. If you do a single compression of the coffee, perhaps some of the edges of the coffee don't get compressed and hence enable fast water flow down that side?

If it wasn't due to tamping, the next thing to question would be the water distribution coming out of the shower screen - is that evenly distributed?

THese are the first thoughts running through my mind - I'm probably completely wrong!

N.B. I sometimes get uneven distribution despite having a pressurised portafilter (i.e. all of the coffee comes out of a single tiny hole in the basket). This is surprising, and I would have thought the reasons I said above wouldn't apply!


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## RoloD (Oct 13, 2010)

Thanks Fran.

I don't think it's the tamping. I 've just run some water through with no coffee in the basket and it still pours more on the left than the right.

Any other ideas?

Roland


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## Glenn (Jun 14, 2008)

Is your bench level?

How old is the group seal? (and do you leave the portafilter in when the machine is off?)


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## Osh (Jun 15, 2010)

The shower holding plate has (from memory) 4 holes for the water to exit. This then disperses equally through the shower screen. If you haven't descaled your machine recently, and removed the plate, as described in many other posts, it's possible that water isn't flowing equally through these holes.


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## RoloD (Oct 13, 2010)

Glenn said:


> Is your bench level?


 It's a marble worktop and the Gaggia itself sits on a Gaggia base unit. It is possible this is not quite level - last time I looked at it, it was only marginally out. Is it possible a millimetre or two could make a difference to the flow?



> How old is the group seal? (and do you leave the portafilter in when the machine is off?)


I think the seals are good - would that affect the flow? It doesn't leak around the top of the portafilter.

I take the portafilter off when the machine is off.

Thanks for your help.


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## RoloD (Oct 13, 2010)

Osh said:


> The shower holding plate has (from memory) 4 holes for the water to exit. This then disperses equally through the shower screen. If you haven't descaled your machine recently, and removed the plate, as described in many other posts, it's possible that water isn't flowing equally through these holes.


Yep. The machine is descaled every month, showerscreen cleaned every week, the holding plate has been scrubbed too.


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## Glenn (Jun 14, 2008)

RoloD said:


> Is it possible a millimetre or two could make a difference to the flow?


Yes but not a huge amount if only 1-2mm

The other question about leaving the portafilter in is that if the gasket has hardened on an angle then the portafilter may not be sitting in level, therefore the portafilter may drop in one direction and the water will naturally head that way

How many mls are in each cup (eg Weigh the cups, then run the water for 25 seconds and re-weigh the cup)

Is the difference only a few mls or is it greater than 5mls ?


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## RoloD (Oct 13, 2010)

Glenn said:


> How many mls are in each cup (eg Weigh the cups, then run the water for 25 seconds and re-weigh the cup)
> 
> Is the difference only a few mls or is it greater than 5mls ?


OK. I ran it with the portafilter, double basket, no coffee into double espresso cups.

First run - 81g in the left cup, 65g in the right.

Second run - one penny under each of the two left feet of the Gaggia - 60g in the left, 56 in the right.

Third run - two pennies under each left foot - 64g in the left, 66 in the right.

So the level does seem to be the issue - and all I need is something slightly thinner than two pennies.

Just tried it with coffee and the difference between the two cups is about the same as it was in the last trial (just slightly more in the cup on the right).

The problem seems to be solved EXCEPT using a spirit level, the machine in now leaning the other way. Should I care?

Thanks very much for your interest and help in this rather minor problem.

Roland


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## Glenn (Jun 14, 2008)

Thats close enough.

Haven't thought to use pennies before


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## BanishInstant (Oct 12, 2009)

RoloD said:


> Yep. The machine is descaled every month, showerscreen cleaned every week, the holding plate has been scrubbed too.


Have you tried monitoring the waterflow without the showerscreen in place, checking the four holes as Osh suggested?


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## RoloD (Oct 13, 2010)

BanishInstant said:


> Have you tried monitoring the waterflow without the showerscreen in place, checking the four holes as Osh suggested?


Good idea, I shall try that.


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## Mazza (Aug 11, 2010)

I had this problem too, it was due do my sloping work surface having had a beer fridge on it for a year. Shame the Classic doesn't come with adjustable feet but then I suppose most peoples surfaces are level !


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