Raising a burr is optional when your knife is still fairly sharp and undamaged, but you just want to bring it back to perfect sharpness. If that is the case, and if you know the angle on the blade ...

Sharpening knives might seem like an esoteric domain ... build a new edge by starting with a coarser stone until you’ve built up a burr that you can see and feel. “We like to say ‘No burr ...