Hi!
I consider buying a La Pavoni. After reading a lot of reviews and watched even more videos on You tube it is still not clear to me if it is possible, in an easy way, to brew a double shot on La Pavoni. A shot like 18 grass in and 38 g out, pretty standard. By the way, light roasted coffee.

18 gram doses are really not the strong point of La Pavoni. The volume in the grouphead and brew chamber are limited and the ground coffee will hold part of that water. I get 33 to 38 grams regularly for my 15g dose with one pull.

You could use a deeper basket, the 20g one, and dose 18g easily, but I doubt you would get 36g out with "normal" preinfusion times and just one pull. So, apart from the issue of high doses and perhaps too thicks a coffee bed which in my opinion do not work well in general, you would have to do some kind of fellini or double pull technique. I haven't done any comprehensive testing nor found anyone prove anything reliably one way or the other but I would be worried about two things:

- the puck breaking and thus get channeling
- getting hotter water for the second part of the pull because the grouphead got filled with fresh hot water from the boiler during the first pull or half pulls

With these caveats in mind, yes you can pull a shot 18g to 38g fairly easily. Will it be good is the real question. The machine IMHO is not built for those doses or volumes, but rather excels at lower doses (14 or 15 grams) and ratios up to 1:2.5 max.

Ah the double pull. So yes you can get the weights you are hoping for. To dose 18 grams though you will need a naked portafilter and a larger basket. The standard baskets are maxed at 15 grams.
To achieve it requires a double pull and some practice. Key is slow lever lift to minimize puck disturbance. Plenty of La Pavoni users do something like this. There are probably numerous threads that will include some lever techniques to make it work.

Results. Since I got a bottomless I have been pulling about 1/3 of my shots with the 20 gr Ims competition basket. Lol. It's so much coffee I wouldn't even think to pull only with one lift. Just a wasteful dose with such low water.

Maybe using a puck screen might reduce puck disturbance on a double pull on a Pavoni.

Puck screen couldn't hurt. No matter what though using double pull techniques will require more frequent pull, clean and lube cycles for the grouphead. It just can't be helped. This also is true of blooming and Fellini pulls as well to a lesser extent.

Sure. Still seems over to my sensibilities but that is me having been using 15 gram baskets for years either one pull or two, blooming or straight PI, etc. A few single baskets here and there. Larger baskets at home are new to me. "20" grams is pretty much in triple ristretto style range. Not sure I need to retro the 00s in Seattle. Is 20 years retro able? I thought the rule was thirty plus.

I have mostly been near 18 grams as my target with the coffees I have to enjoyed in that basket. It has really been with higher body chocolate berry bombs, so I am guess I am going retro. My forays into light stone fruity coffees with it lead me quickly back to my standard basket but they are more work no matter.

I have not been doing decaf as much lately but was thinking the same thing since I tend to up the coffee intake in the dark half of the year. Half caf blends I make would definitely benefit from the added space.

Been having trouble sourcing worthwhile decaf around here.

I think the 20 ims was a worthwhile purchase as an added tool in the box for a change of pace or with specific coffees.

I am doing long preinfusions for very light roasts and let 5-6 grams drip through before the pull. I also quickly but fully (lever totally up) flush before each pull to get rid of the air pocket. I get 45 grams in the cup if desired, no problem.