Global believes the quality of their knives guarantees you will never need to sharpen their bread knives. Nor do they recommend doing so. That being said, if for some reason you absolutely must sharpen your Global bread knife, then use a sharpening steel that is the same width as your blade’s serrations, and sharpen the knife tooth by tooth. If a burr forms on the flat side of the knife, then run the burr over the sharpening steel once.