Denis wrote:And you believe a Teflon burr holder is equal in alignment with a steel burr holder?
Look at these pictures, the vario's where having alignment problems after few kilos in Europe because here we use really light beans.
Your posts are very good and informative. But you keep referring to the Vario burr holder shelf as "Teflon". While it is clearly a polymer material, it would be an engineering blunder of the highest order to use PTFE in an application requiring rigidity. Further, PTFE tends to be pure snow white. For this reason, I doubt it's PTFE, though it's clearly a polymer material. So the next question becomes, "To what extent does that affect alignment?" As far as I know, nobody has done any actual measurements here. While plastic connotes flexibility, it depends on the force applied. There are plastics you couldn't come close to flexing with ordinary forces, for example. Are we certain the upper burr of the Vario flexes under bean load? And finally, there's this, which is big enough to me, that it can't be dismissed out of hand:
Jake_G in another thread:
Likewise, a burr geometry that yields a tight distribution (such as "unimodal" burrs) will taste better at high extraction yields than a burr geometry that yields a wider distribution (or "bimodal" burrs). Conversley, the wider spread will taste better than the tight spread at low extraction yields and the one constant is that they will taste different from each other at the same extraction yield...
IOW, tight unimodal distributions from perfectly aligned burrs at ultra high EYs are not the only pleasant flavors in espresso, even if they are
the latest hotness. Anyone remember not so long ago when super ristretto was the hotness? Some burrs are intentionally designed NOT to be unimodal.