An Etymological Dictionary of the German Language/Gerste
Gerste, f., ‘barley,’ from the equiv. MidHG. gërste, OHG. gërsta, f.; akin to Du. gerst; a specifically G. word, unknown to the other dialects; OSax. and AS. grîst, E. grist, are not connected with it, but with OTeut. grindan, ‘to grind’ (equiv. to Lat. frendere, ‘to gnash’?). In the remaining Teut. dialects the terms for Gerste are Goth. baris, OIc. bygg (and barr), AS. bęre, E. barley. OHG. gërsta, from pre-Teut. ghérzdâ-, corresponds only to the equiv. Lat. hordeum (from *horsdeum, prim. form *ghṛzdéyo-); Gr. κριθή, ‘barley,’ is scarcely a cognate. From an Aryan root ghrs, ‘to stiffen’ (Lat. horrere for *horsere, Sans. hṛš, ‘to bristle up’), some have inferred Gerste to mean orig. ‘the prickly plant’ (on account of the prickly ears).