u/hgca

Background: I'm not an espresso noob, but am not an expert either. I drink an oatmilk latte every morning, and that's pretty much it. Like most people here, I enjoy the ritual of making my morning coffee. I have a Breville Infuser and a Breville Smart Grinder Pro, which I've had since 2019.

Recently I talked myself down from buying a new espresso machine (I know I know, upgrade the grinder first!), and instead picked up a bunch of shiny new accessories from Breville. One such accessory is a bottomless filter! I was pleasantly surprised that my puck prep didn't need to be tweaked that much, but I definitely am getting some sputtering when I pull my shot. It doesn't happen with every kind of bean, but it happens with the ones I buy most often (Zab Jolly Roger).

My process:

1. Dial in every time I buy new beans, which I get from local coffee shops here in Montreal. 19g fresh ground beans, 38-40g espresso in ~30-35s (I know if could be more perfect, but for my taste buds this is good enough!).
2. I let the machine warm up 5-10 minutes with the portafilter in, then go to puck prep.
3. Puck prep: grind beans directly into my portafilter using the funnel, tap tap the side of the portafilter, WDT tool, then a couple spins of the leveler. Tamp, add puck screen, then pull the shot.
4. I run water through the group head as the beans grind, and then run some more water after pulling the shot and wipe clean at the same time I clean the steamwand.

I've tried grinding a little finer, but then the extraction takes way longer. I grind around 8 or 9 on the Breville grinder, if that tells you anything. I have been digging through this sub since I know this question gets asked all the time, and the only thing I've found is someone saying that seeing the start of the shot coming from the OUTSIDE of the portafilter (rather than the middle) is a sign of bad puck prep / channeling. But I'm not sure what I can do to resolve this that I'm not already doing?

I've done a full descale, and I removed the group head to do a deep clean. The water admittedly doesn't flow through it perfectly evenly, but again not sure what else I can do. I don't know if the machine itself being level is a thing, but my floors are a bit slanted.
Another small but maybe relevant thing is that the pressure gauge hasn't worked for about 4 years :).

Anything I'm not thinking of? Please, all advice welcome!