I believe I have the exact machine as you. I don't have any magic bullet advice to offer, though I want to reassure you that great shots with lots of crema are definitely possible with it.

I've been "practicing" on mine for 5 years, and consistent microfoam still remains elusive. But, as for the shots themselves, some taste better than others -- of course! -- but they seem to be usually in the neighborhood of proper extractions.

I agree that these examples definitely look way over extracted.

In addition to the obvious: fresh coffee, proper grind, tamp, etc, I would suggest you play around with variations of the "fellini move" -- leaving the lever in the up position for a number of seconds to start preinfusion of puck, and then, lowering and raising it a few times (try experimenting with different speeds) before finally pulling the shot.

Not only does this help with infusing the puck, but it may improve the resistance in the lever too. Not sure why! (Many have written about it). If I don't have resistance and the coffee doesn't start to come until the lever is level, when the first drips come, I raise the lever all the way up again, wait a few secs, and then pull through.

What I've just described very sloppily is a rough example of the fellini move.

Keep playing and practicing. You will have your Eureka moment! And then, the next time you pull a shot, it will completely disappear!!

Part of the fun!

That link is very helpful understanding what to expect and what needs to be changed.

I think I'll stop dosing more than 15g. I'll use 12g-15g tamp hard enough and see the results.
If it's still not good changing the grinding level will be the next step.

And if that doesn't work may be your next step should be questionning your grinder itself...I suspect that a good quality electric burr grinder should turn things a lot easier for you.

Is that a full pull in your shot glass?

If yours is an early Pav the explanation could be that you have one of the nylon pistons and that it has unscrewed a bit, limiting its travel.

With an empty PF in the machine, pull the lever up to the top. Does the steaming water come cascading forcefully out of the sides of the portafilter spouts or not? Be careful when you do this. It should spurt over the sides of teh tray and base and the water will be very hot.

How old is your machine?

Cheers

Mike

The shots in the photos are a full pull. (with double basket)
When pulling with empty PF the water do come out of the sides forcefully. I also think I have enough force when opening the steam.
I did not buy this machine. I got it from a second hand. I can only guess it is about 3-5 years old.
I also put it to service at the local Pavoni reseller. It was decalcified and some gaskets where replaced.

How do I check the piston problem?

I ran a couple more tests this time with no dosing, only filling the double basket to the top leveling it with the back of knife and then tamping.
I still get over extracted shots more or less like in the first images.
I also noticed that the first pull is easier than the second and third. Is that normal?

Assuming I do get over extracted shots what should I try now?
I hope I won't have to get an electric grinder before I can prove myself I can get decent shot with this machine. If needed I can use the local shop professional grinding.

I made a few more tests.
This time I decided to keep the dose and tamp the same. I dosed a full double basket cleared it with the back of a knife and tamped hard.
I played with the grind level. I first got over extracted shots.
Then I got the following shot. It's one of the best I got so far. It was also less bitter than previous shots.
I know it's still far from being a good one but I may have some improvement.
I'll keep testing different grind level to see if there is any difference.

I dosed a full double basket cleared it with the back of a knife and tamped hard.

Believe it or not I dose even a little fuller. I dose with the basket out of the PF on a flat surface. I pile the grind over the basket rim in a cone, then tamp it down (the video link below shows a stylized version).
http://www.home-barista.com/lever...r-video-t1961.html

You have not said what the coffee is, and when it was roasted. It looks for some reason to be old? The shot volume still seems to small for one LP pull. Was the lever very difficult to pull down? if so, you could grind a little coarser.

Nice video. Do you know what KyM model are you using?
I'm also using KyM grinder and I'm trying to find the right grind level.
Can you try to describe how difficult how much the burrs are touching in your grind level?
(I use a grind levels where the burrs a fully touching and I can't hardly turn the handle without beans)

The coffee beans are a bit old. They are a few months old but have been in vacuum till I open the package 2 days ago. Do you think it's OK?

The glass I used in the photos is not so small. It is a 9oz (0.271).

I also had a few tests today, same dose and tamp with different grind levels.
When grinding fine I get bitter oily stuff. When grinding coarser I don't get enough pressure and just a watery looking espresso. I think I'll buy fresh beans keep trying...

Its all about the beans. Fresher beans will do the job, and you may need to open the grind a little or you'll choke the machine.

Try a freshly roasted espresso blend and your problem will be solved! Good luck, and lets see a photo,

PC

sbenyo wrote:
The coffee beans are a bit old. They are a few months old

That was the missing clue...