Ceramic is harder than knife steel. Even grandmother knew this and therefore liked to sharpen her kitchen knives on the edge of the plate of unglazed porcelain to keep the blades serviceable. The only easier way to resharpen is with a sharpening rod made of the appropriate material. Our version offers two grinding surfaces with different grits in one rod and can therefore be used not only for resharpening (braun), but also for fine honing - i.e. polishing (white) - at the same time. A few passes are sufficient in each case. To do this, either place the rod vertically on the table, hold the olive wood handle with one hand and with the other hand guide the cutting edge along the grinding surface at an angle of about 15-20° with light pressure. Or, proceed in the same manner while the sharpening rod is on the work surface in front of you. You can tell if you are "hitting" the edge by the noise, which should sound softly sandy (not loud and scraping), and you will also feel it if you can make the movement in one go.
The sharpening rod does not need to be watered before use. Metal abrasion accumulating over time will leave visible marks on the sharpening surfaces, but will not affect functionality. You can occasionally damp clean the ceramic with the roughened side of the pot sponge.