This wasabi grater is the best we have found so far second only to the real and traditional shark skin.  It makes a fine, creamy wasabi paste.  The wasabi heat and flavor is retained in the root (rhizome's) cells.  Each cell wall that is broken during grating releases that heat and flavor.  Thus, the finer the grate, the more cell walls are broken and the more/better heat and flavor.  The way to tell is the creaminess.  More creamy texture means more cell walls broken.  (Grater is free with one pound or more of wasabi root purchase.)

This grater can also be used for ginger, horseradish, garlic and other items.