Shark Skin Wasabi graters (Oroshi) are the traditional tool of choice for Itamae faced with grating authentic fresh wasabi rhizomes. While mico-planes, metal or ceramic graters work reasonably well, the unique rough sandpaper like surface of shark skin is ideal to break down the dense texture of wasabi to produce the perfect creamy consistency that fully releases wasabi's nuanced flavor profile.
Best practices include patient circular grating with steady pressure, gradually producing the right texture whil mixing it thoroughly with the constant motion. Also good for Tumeric, Ginger or Horseradish.