Belgian whetstones are used for sharpening the knives.

These whetstones consist of a natural stone quarried from the Belgian Ardennes mountains. The lighter layer is used for grinding, the slate layer on the bottom is simply to make the sharpening stone stronger. The Belgian whetstones must be wet before honing. Set the blade onto the stone at a sharp angle and pull it back in circular motions. A natural abrasive paste develops in this process, which sharpens the blade and polishes it finely at the same time.

BB 4