An Etymological Dictionary of the German Language/Annotated/Grütze
Grütze, feminine, ‘groats, grit, brain,’ from Middle High German grütze, ‘water-gruel’; a variant of the equivalent Middle High German griuȥe (griutze?); Old High German gruzzi (whence Italian gruzzo, ‘pile of collected things’); compare Anglo-Saxon grŷt and grytt, English grit and groat (from Anglo-Saxon *grota?), Old Icelandic grautr, Dutch grut, gort, ‘groats.’ From Old German the Romance cognates, French gruau, ‘groats,’ are derived. Besides Grieß, Middle High German grûȥ, ‘grain,’ is also allied to Grütze; hence ‘grain’ may be the primary meaning of the Teutonic root grū̆t, with which the primitively cognates Lithuanian grúdas, ‘grain, kernel,’ and Old Slovenian gruda, ‘clod,’ are also connected.