charlesaf3 wrote:It's possible/likely I need to change something with the new machine.

Not just machine. It's all about finding the right parameters and techniques to get the grinder, basket, and machine to play nice.

The tamper is probably the least important factor in getting perfection. If the other three are playing nice, you will have to purposely try to screw it up with the tamper, otherwise any tamper would suffice, IMO. But I think one that has a convex base does allow the extraction to develop more even on the underside if watching the pour is important to your experience. A convex basket bottom also contributes to faster centering of the flow.

It takes considerable effort, trial and error to find the right "formula", if you will, to everything playing nice together.

Sorry, yeah, that's what I meant. I changed coffee, and I think the local Kenyan is a big part of the problem. Trying Stumptown hairbender.

I've always liked convex tampers (ok, last 7 years or so) but I see the zeitgeist is changing to flat.. So I ordered the Joe Frex interchangeable ones from whole latte love, to see which I prefer currently. My issue with the LM tamper is that the top digs into my palm.

Interestingly, to me, my channeling issues have been in the center of the puck, not the sides. So I'm wondering if that means I should move to a flat.

charlesaf3 wrote:channeling issues have been in the center of the puck, not the sides. So I'm wondering if that means I should move to a flat.

from my experience channeling is largely attributed to poor distribution of fines, but I suppose it won't hurt to try a flat tamper if you think it helps.

Yeah, that's been my experience as well. Thought tied try the flat to see if it changed the distribution - I did flat until the Vivaldi, then found convex worked better for that machine