Base Knock Convex
All KNOCK-CONVEX bases have a slightly outwardly curved surface for pressing the espresso and are manufactured from solid stainless steel on a CNC lathe. Similar to the American Curve, the difference between the center and outer edge is 1.5mm.
Why the name Knock?
After the first tamping of the espresso, the side of the portafilter is lightly knocked, which causes all espresso grounds from the side edge to fall into the portafilter. Then it is tamped again. So that the tamper base doesn’t have to be used for this light tap on the portafilter, which could damage the soft portafilter, or even the wooden handle, the integrated silicone ring in the base can now be used for knocking. We have legally protected this invention.
Why Convex?
Normally, the surface of the tamped espresso in the portafilter plays no significant role; whether flat or convex, there is enough space between the espresso surface and the shower screen so that the water can distribute evenly over the espresso and also penetrate the espresso grounds evenly. However, if flat baskets are used or significantly more than 7g (1-cup basket) or 14g (2-cup basket) is used, there may be insufficient space between the espresso grounds and the shower screen for optimal brewing water distribution. For this purpose, a Tamper Base Convex can be used, which leaves a depression in the center for better water distribution.
