Dogshot wrote:I recently changed machines, from a Gaggia Classic to a Brewtus II. My flat-based Reg Barber was great with the Gaggia, but I was getting pin-holes near the centre of my pucks on the Brewtus (because of the the convex shower screen?).
So I pulled out the pos plastic tamper (which is convex) that came with the Brewtus, and I use the flat-based Reg to do my NSEW and the pos convex plastic to do my 30lb tamp. Now, I am using the Weiss Distribution technique, and getting pucks with zero evidence of channeling maybe 30% of the time, so I am very happy with the results. In the interest of parsimony, however, I would prefer not to use 2 tampers when building a puck, but the pos cannot be used to do a NSEW tamp that works.
My question is, will a Reg Barber convex tamper permit a good NSEW tamp? If not, how do you use a convex tamper?
Thanks,
Mark
Hi Mark! I've got one flat base and one convex base tamper (oh yeah, a flat base Espro too

), and I find the convex base to be slightly more forgiving. This was true on my Rancilio L7 (flat shower screen) as well as my Vetrano, so I don't think it's just the shape of the shower screen.
I like to play around with different tamping styles, but a simple one works as well as anything for me: tamp in the center, brush off rim and invert PF to remove excess grounds, then tamp hard (I tend to use over 30#) in the center, rotate with no pressure to polish.
HB wrote:For those who are scratching their heads saying "who is Weiss?", I believe it refers to RapidCoffee's stirring with a pointy implement...
Um, I think Mark coined the name. And the pointy implement would be a dissecting needle. See the link for more details.
Not many people have dissecting needles lying around, so (with Dan's permission) I'd like to offer one to any HBer who wants to give this a try. I just ordered several dozen (they're very inexpensive). I'll be glad to mail one to anyone who sends me a self-addressed stamped envelope. Until they run out, anyway. Just my way of saying thanks to the community. Dan, is this OK with you?
- John