Intermittent low shot volume on La Pavoni Europiccola - Page 2

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Vereto

Postby Vereto » Jul 13, 2018, 12:12 am

Makes sense. My machine does hiss while warming up and is silent once it is up to temp. Thanks!

mazur

Postby mazur » Jul 13, 2018, 1:44 am

Note that when you purge the air properly out of the group, you will feel resistance immediately during the pull. If I don't purge properly, I usually pull the lever 50% of the way before I start getting any flow.

To get to that point I have noticed that I need to get the group very hot. I do at least 5 strokes of the lever up and down completely and quickly and then hold the lever up and purge water for a couple seconds. When done right, the rate at which water is expelled gets more vigorous and steamy. Note that this is on a Pro, so I expelling some extra water is no biggy for me.

Vereto

Postby Vereto » Jul 13, 2018, 9:53 pm

Interesting. 99% of my pulls don't have resistance till roughly 50% of the lever throw.

So to purge correctly, you draw water out without letting the lever come back down?

jtrops

Postby jtrops » replying to Vereto » Jul 14, 2018, 4:25 pm

Purging the group, or flushing as we called it earlier, is what mazur was referring to. In order to make sure that I have moved as much water into the group before placing the PF (portafilter), I do a short flush to just let water come out of the group, and then hold the lever just when it stops flowing. Then I put the PF in and start filling the group. This, along with having a hot enough group, makes it so that my lever feels resistance immediately when I start pulling down.

If you feel sponginess in the lever as you pull it means you are compressing air that is still in the cylinder.

RHP

Postby RHP » Jul 15, 2018, 7:46 am

I think all the advice on here is spot on, as you'd expect. The only thing I'd add is just to not be put off by the apparent tediousness of the early learning curve. I believe I've had mine a couple of years now and my first results were pretty average and very inconsistent. But now I can just eyeball the amount of beans I'm using have the technique down (for my machine) for pulling a good shot. I found weighing the beans really important early on for learning how they were affecting the shot but once I had it dialed in, I put the scales away. I might get them out occasionally for a new coffee but I'm not one for weighing every single time when I really don't need to. My shots come out at around 30 grams, which is with pulling a little extra through at the beginning. I like the texture and intensity around here (Cortado or macchiato, usually). I can let more water in if I like but it's not as good for my tastes - you have to love this control it allows you once you get a knack of it!

My "shots" are the regular double basket on the newer machines (51mm?). So I guess you might call this a "double shot" but if you read about these do get confused a bit, as there obviously is a single shot basket with the La Pavoni, but it's not used as commonly. I've grown to really like the size though, you get a great texture out of the regular "double" shot. I like that it's gives me a small and intense coffee in flavour and fully satisfies me, but isn't throwing me through the roof with caffeine either.

Vereto

Postby Vereto » Jul 15, 2018, 3:25 pm

Ok pulled 3 shots this morning, all of them 14g.

Started by letting the machine warm up for 20 minutes. For each shot, I did 5 slow flushes to try and heat up the group head. Then I pulled 2 oz of just hot water to heat the cup. Then I pulled the handle up slowly until I heard water just start filling the chamber and immediately stopped, pulling back slightly. I secured the PF and proceeded.

Shot 1: On pre-infusion, I felt minimal water entry. I only felt back pressure around 10 degrees below horizon of the lever and the shot yielded 18g.

Shot 2: (<5 minutes later). This time, I felt much more water entering the chamber. Still no back pressure until horizon (my typical experience) but the shot was 27g. Tasted pretty good but I wanted more crema.

Shot 3: (20 minutes later) This time, thinking I was not getting enough back pressure, I reduced the grind on my Lido E by 0.5 marks. This time, I felt/heard a good deal of water entering the chamber but when I pulled the lever, I had no back pressure essentially all the way down. The shot was perhaps 4 drops but the lever was easily pulled to baseline. I looked at the puck and it was wet but essentially undisturbed. EDIT: In retrospect, I did use an older coffee for this shot as I ran out of my fresh roast... Burning through so much coffee trying to get this process down! I should have some new fresh beans tomorrow.

Any thoughts?

Thanks. (Don't worry RHP, still loving this hobby)

EddyQ

Postby EddyQ » Jul 15, 2018, 10:46 pm

Shot yield of 18gm is VERY low. And you are sure your pre-infusion was such that lever was fully up until drips came out before you lowered??

Another wild thought is that you may have worn lever pins. Worn pins can reduces the amount of water entering by essentially not opening the hole all the way. I think this is a long shot based on your info. You say you hear water gushing in, so I suspect there is no issue with your pins and water entry.

Could your piston be adjusted too high? It should come down and just about touch the shower screen. I'm not sure if this would cause such a issue with shot volume, but I suspect it may.

RHP

Postby RHP » Jul 16, 2018, 5:50 am

Vereto wrote:
Any thoughts?



I suspect your temps are all fine, your dose is consistent, but perhaps the simple lever action is being over thought a little.

I don't believe you should require excessive force to pull the shot, like you may see in some videos online. Pressure is needed but it needs to be a consistent, even pressure that gradually releases the shot, rather than firing it through. If you feel too much resistance, I usually find the dose is too high (not your case) or the grind is too small (could be your face).

When you move the lever up, with the portafilter locked in ready to go, just move it all the way to the top and wait 20 seconds. You can guarentee it'll be full and infused by then.

If coffee runs out immediately or after only a second or so, I found this meant the grind is too large or the dose too small or both.

Some say, and I think it may be preferred (?) that you should get a small run of coffee after 5-6 seconds, at which point you can pull the shot. BUT I don't believe this has to be the case, as you can work in your grinder to get the right amount of resistance in the pull and infusion. Mine is dialed in so it preinfused for 10-20 seconds but with no "drip" - but I can ease in as much water as I want, ultimately.

You will go through a few bags of coffee but always get good, fresh coffee. Don't be tempted to get some old crap from the supermarket, it'll just make your results more inconsistent and confusing!

Unless there is strong evidence / reason to believe the machine is faulty, I'd just keep working on the technique with fresh coffee for a good while first.

Vereto

Postby Vereto » Jul 16, 2018, 5:32 pm

EddyQ wrote:Shot yield of 18gm is VERY low. And you are sure your pre-infusion was such that lever was fully up until drips came out before you lowered??


I think this is one of the fundamentals I have been missing. Today, I lifted the lever up to pre-infuse and waited for drops to fall. I gave it 90 seconds and saw nothing. I pulled the shot and got 23g out. Could the missing drops be because I do not have a bottomless PF (ordered, waiting to be shipped) and are adhering to the inside of the PF? I doubt my grind is too fine as I have yet to choke the machine out.

EddyQ wrote:Another wild thought is that you may have worn lever pins. Worn pins can reduces the amount of water entering by essentially not opening the hole all the way.



Another interesting thought as my pins are a little worn and the lever has quite a bit of play. I have ordered some new ones and they are being shipped with the bottomless PF.

-----

I did 5 shots today and 3 of them came out ~10g. I would say the lower output shots were with a tighter packing as I'm still trying to get more back pressure when pulling the handle. Out of all my shots, I am still not feeling any resistance until below the horizon. I figured giving more time for pre-infusion + tighter packing would lead to more back pressure and more crema. The shots I have been pulling for the past several days have been with low lever resistance and just enough crema to cover the top of the shot.

So my questions for the day are:
I I am not seeing drops out of my PF after 10-20s, do I need to make adjustments to my grind or packing?

Are there any glaring errors in my logic that might be leading to such low back pressure?

EddyQ

Postby EddyQ » Jul 16, 2018, 7:39 pm

Vereto wrote:I think this is one of the fundamentals I have been missing. Today, I lifted the lever up to pre-infuse and waited for drops to fall. I gave it 90 seconds and saw nothing. I pulled the shot and got 23g out. Could the missing drops be because I do not have a bottomless PF (ordered, waiting to be shipped) and are adhering to the inside of the PF? I doubt my grind is too fine as I have yet to choke the machine out.


After 90 seconds, if your preinfusion is correct, you should get drops. 20 seconds should give you drops. It could be your grinder has fines that make for slow preinfusion. My Lido E is like that and I now pull the lever with a little pressure until I get drips. Then slowly return it to fully up position followed by the final pull. I do have a bottomless PF which makes it easy to see what is happening. But I think you should get drips with spout PF with this method.