Why do you think there's a correlation between pressure and shot volume?

 

my thoughts are that you get a big change dependent on grind and how much you pre infuse , holding the lever at the top of the shot for 10 seconds gives me consistent weights shot for shot

 

Reduce the amount of coffee you're putting in. You're probably over filling the puck. Drop it to 14g and you'll see the output increase.

 

Thanks for the replies.

Here are some further comments.

Grind size - I use the same coffee with same grind size and the

shot volume varies, without change in grind.

10sec Preinfusion - This is what I am doing already.

Dose weight - I'm not sure this is the issue, if I use a mini Fellini

move then I can achieve a consistent 25g shot from 15g dose.

By "mini Fellini" I mean, pull up lever let water in, close lever a fraction

then lift lever again.

 

interesting - I'm not a Fellini wiggler myself, one thing this reminds me of is when i found that I had to jam the lever at full lift to get any water at all, of course what was happening was the piston was becoming loose on the shaft, more common with the Teflon pistons than the brass.

The other thing I'm thinking is if the beans are an oily type they are more resistant to the pre infusion, The Pavs are quite sensitive to dose weight even by 0.2 of a gram making a noticeable difference?

 

So, I. The new proud owner of a millennium Europiccola, and, oh boy, it's a learning curve and a half!

I'm currently dosing 16g into the basket, and I'm getting approx 28g out, without any special manoeuvres.

 

interesting - I'm not a Fellini wiggler myself, one thing this reminds me of is when i found that I had to jam the lever at full lift to get any water at all, of course what was happening was the piston was becoming loose on the shaft, more common with the Teflon pistons than the brass.

The other thing I'm thinking is if the beans are an oily type they are more resistant to the pre infusion, The Pavs are quite sensitive to dose weight even by 0.2 of a gram making a noticeable difference?

Hi thanks for the comment.

I am not a fellini type either, causes chanelling etc, it was just to point out there is room above the puck for much more

water than I am currently getting with a normal lever lift.

Do you think the piston needs adjusting ?

Regarding beans, definatley not oily, thank god !

 

Hi thanks for the comment.

I am not a fellini type either, causes chanelling etc, it was just to point out there is room above the puck for much more

water than I am currently getting with a normal lever lift.

Do you think the piston needs adjusting ?

Regarding beans, definatley not oily, thank god !

Reduce how much you're putting in the basket. Some beans I can get 15g and others I have to drop to 14g. It makes a massive difference. The Fellini method makes no sense to me.

 

The 'mini fellini' won't cause channeling. You might well disturb the puck going down half way and pulling back up slowly to refill the group but by gently pumping up and down at the very top of the pull until all of the air is out of the group and the pull doesn't feel spongy at the start you'll get more volume/weight out. I didn't worry about pre-infusion length at all as there seemed to be no real difference between 10 seconds and 20. Of course starting the pull at a low pressure will mean a faster flow when up to full pressure compared to starting at full pressure. I've good memories of pressure profiling with the pav.

 

Hi

Thanks agian for the comments.

I have tried 14g, which does make a difference - I managed to get 26g out which is a new record !!

I then tried marking the piston with a pen, to find the exact lever position height before water

flow.

This enabled me to lock the portafilter in, with minimum extra air gap as the lever

rises for water inlet.

This gave me shots of 30g,29,27g, & 30g .

I then tried timing the lever lift with the p-stat switching on, so efectively getting max

water pressure with water inlet.

Interestingly this gave an increased shot volume of 35g and 37g.

So a combination of lower dose, minimum air suck from lever lift, and timing the

shot for highest water pressure seems to get the maxium shot output.

I finally tried making the grind coarser, which resulted in a 41g shot !

But the 30g shots tasted better

 

Hi

Thanks agian for the comments.

I have tried 14g, which does make a difference - I managed to get 26g out which is a new record !!

I then tried marking the piston with a pen, to find the exact lever position height before water

flow.

This enabled me to lock the portafilter in, with minimum extra air gap as the lever

rises for water inlet.

This gave me shots of 30g,29,27g, & 30g .

I then tried timing the lever lift with the p-stat switching on, so efectively getting max

water pressure with water inlet.

Interestingly this gave an increased shot volume of 35g and 37g.

So a combination of lower dose, minimum air suck from lever lift, and timing the

shot for highest water pressure seems to get the maxium shot output.

I finally tried making the grind coarser, which resulted in a 41g shot !

But the 30g shots tasted better

Incredible! Do you have a pressure gauge on yours?

 

Hi

Yes, the one with the sight glass and gauge.

Although if you have good ears you can hear the Pstat

switch on with a non-gauge machine.

 

Hi

Yes, the one with the sight glass and gauge.

Although if you have good ears you can hear the Pstat

switch on with a non-gauge machine.

Sure, mine has a light that can tell me when the P-stat is kicks. But I don't know what pressure it is at

 

Sure, mine has a light that can tell me when the P-stat is kicks. But I don't

know what pressure it is at

For my experiment I'm not sure it matters what the actual pressure is.

More the fact that when the boiler coils are switched on by the Pstat thign, the boiler is rising to maximum pressure,

which would then presumably help push as much water as possible into the group.

 

Pstat staying on longer makes water hotter. The pstat switches the heating element on/off... the longer it is on the more heat it creates which in turn creates more pressure... think steam engine. All of that will change the taste of your coffee... Pstat is an abbreviation for pressure stat... Does that sound right or did I just make that up!? Sounds feasible?

 

Hi

after a long time I have discovered the problem !

i read somewhere it can be caused by the piston head being loose.

I took the lever apart, and indeed the piston head was loose.

Screwed back on tight, reassembled, and now the shot volume is back on target.

Now I have increased dose back up to 15g, getting 30+g brew weight out !

Great

 

Whenever I clean the basket from my europiccola after brewing, I can always see a heavily impacted coffee puck, I can imagine the vapor water mixture forces onto the puck when it gets into the group head, no idea how to fix it, or it's just not a problem.

 

Whenever I clean the basket from my europiccola after brewing, I can always see a heavily impacted coffee puck, I can imagine the vapor water mixture forces onto the puck when it gets into the group head, no idea how to fix it, or it's just not a problem.

How does the coffee taste? Post mortem of the spent puck is usually useless and doesn't tell us anything.

 

Try listening very hard when lifting the lever. When you can just hear the water going into the grouphead, then hold into there. This gives you gentle preinfusion and enables you to grind finer. when full, lift the lever fully. At normal grinds I've had espresso peeing out of the grouphead with the lever fully up. Think I'll have to resurrect my Millennium Europicolla as my other half has expressed a desire to have a go after seeing them at the Rave Lever Day..

 

Think I'll have to resurrect my Millennium Europicolla as my other half has expressed a desire to have a go after seeing them at the Rave Lever Day..

Best news I've heard all year! [emoji4]