Lelit Bianca 2 - Consistent puck erosion from shower screen

[Javarick]

I've had the Lelit Bianca 2 for ~ 6 months. I've been doing home espresso for 29 years and have been through a Domena Splendida, Rancilio Silvia, La Cimbali M27, Wega Mininova, and La Spaziale Mini Vivaldi 2, so I'm not inexperienced.

I like the Lelit Bianca except for one small annoyance. Pucks in my 18 gr basket (the only one I use) always seem to be eroded in the middle of the top surface, resulting in a small indentation with a circle of small, deeper erosion pits in it. My work process is to weigh and grind 18.5 grams from an empty hopper, dump into the PF with a PF funnel, even out the dose by tapping the PF, level with the Lelit leveler, tamp lightly, then pull the shot.

My standard grinder is a Sette, and on occasion, I use my Kinu Phoenix. It's the same for both.

This seems to happen consistently no matter what the grinder, grind setting, tamp or dose. I haven't experienced this with any other espresso machine.

Any suggestions? New precision shower screen perhaps?

If so, how do I find out what fits the Bianca 2 without pulling the old one?

[PIXIllate]

Do a Nickle test for headspace and lower your dose.

[Javarick (original poster)]

Thanks, and I should have initially posted I'd done a nickel test after the first few shots to see what was causing it. It's an 18 gram basket and I still get the pattern with 17 grams.

[PIXIllate]

Dose less until there is no nickle imprint.

[HB]

I like the Lelit Bianca except for one small annoyance. Pucks in my 18 gr basket (the only one I use) always seem to be eroded in the middle of the top surface, resulting in a small indentation with a circle of small, deeper erosion pits in it.

Assuming the espresso is good, why is the appearance of the puck post-extraction a problem? Search on "puckology" for discussions of this perennial topic.

[Nunas]

If the Lelit leveller is a cloverleaf leveller, then this is normal and not a problem in the cup (if it's a different leveller, then I've no idea) I noticed the same thing when I bought a Chinese cloverleaf leveller on Amazon. I, too, only tamp lightly or not at all. It takes a short while to 'dial in' the leveller with new beans so that it both levels and lightly tamps. Until I get this right, I tamp a bit.

I have noticed that after my puck prep, everything looks great-nice, firm, level puck. Then when the PF is removed, the puck is concave, and there are sometimes little holes here and there. I note that there's no channeling, so the holes are only superficial. I know this because I can watch the pressure on my group (the gauge came with the flow control). If I lower the lever to mid position, the pressure holds steady, once the air is expelled.

So, what's going on here? I hypothesize that the leveller levels, and the way I use it, it tamps a bit. But, the density of the puck is different from centre to circumference. This, I think, is due to the shape of the cloverleaf. It moves more grinds out to the edge, everything looks level from the spinning action, and then when the water hits the puck, the outside expands more than the inside.

As for the little holes, your guess is as good as mine. I get them with my 'pro' shower screen and with the stock one.

[Javarick (original poster)]

Thanks for the replies above.

Why is this a problem? I don't know that it is, but I never experienced this with my La Spaziale, though that may be due to the smaller diameter PF (53mm rather than 58) and the correspondingly deeper puck since I used 18 grams to dose the La Spaziale just as I do for the Lelit.

A look at my grouphead gasket may provide a clue - it's 6 months old and now has a groove worn/pressed into it that brings the top surface of the puck closer to the screen. I did the nickel test again yesterday after not having done so since I set up the machine when it was new, and presto - the groove in the grouphead gasket narrowed the distance from the top of the puck to the basket. I downsized the dose to 16 grams and no nickel imprint, as well as on erosion in centre of the puck. It IS concave now, but not eroded. The flavour of the shot was not identical, but still very good.

[Javarick (original poster)]

Replaced my shower screen and portafilter with IMS Competition yesterday from Espressotec in Vancouver. (Great to have a well-stocked espresso machine parts and service place 15 minutes from home.) Also replaced the grouphead gasket.

The puck erosion is gone. It will take me a while to fully evaluate the differences in the cup, but it looks and tastes different and better.