Last week I stopped in at Espresso Parts NW which is about a half hour drive from where I live. I wanted to pick up a couple "tools" and was also interested in checking out the convex tamper. I purchased one of these with the short fat round rosewood handle and took it for a spin <or is that a twist?> when I got home. If I was Emeril, I'da hollered "BAM!" because my first shot after using the convex tamper was a perfectly even extraction. It was like I was transformed into a pro.
I was doing pretty well with the flat tamper and all the techniques I was learning here have been quite helpful. The reason I was interested in the convex was that I read somewhere that Schomer at Vivace decided it was a great anti-channeling tool because it forced the coffee to adhere to the side of the basket better during tamp. I thought about that for awhile and it made sense, so I sprung for the custom job. I occasionally have a slight bit of channeling, but it's my own fault for trying to shift the puck to level it after tamping <you know you've done this too
> Even so, what is interesting is that even when I pull one of these goofs, the coffee appears almost right after across the entire mid section, salvaging the shot. I usually just pull for a shorter duration when this happens to insure I am not pulling too much of blonde bitter overextracted coffee along the side where the channeling is occurring.
I think that it is worth a try for anyone who hasn't used one. I swore by my heavy flat tampers for years and now I find it hard to not use the convex unit. I probably should video one of these globby, gloppy sweet ristrettos I am getting with this new tool.
By the way, Espresso Parts NW new store is pretty cool. There are alot of home & commercial, <new and old> machines, grinders, tools, etc, and a VW Van....yes a van in the store near the front counter.
The truth shall set you free....or perhaps not.