An Etymological Dictionary of the German Language/Annotated/Kraut
Kraut, neuter, ‘herb, vegetable, weed,’ from Middle High German krût, neuter, ‘small foliated plant, herb, vegetable,’ especially ‘cabbage,’ Old High German krût, Old Saxon crûd; Dutch kruid, neuter, ‘herb, spice, gunpowder’ (the last meaning is also found in Middle High German from the 14th century); Middle English crûdewain (Dutch kruidwagen), ‘ammunition waggon,’ seems to have been borrowed. Gothic *krûþ (genitive *krûdis), neuter, might be taken for krû-da-, with the suffix da- from tó (Aryan grû-tó-). Greek γρύτη, ‘lumber, trash,’ does not agree in meaning. Perhaps the word should be connected rather with the Greek root βρυ- for gru; compare βρύω, ‘to swell,’ ἔμβρυον, ‘embryo,’ βρύον, ‘moss.’ From German is derived French choucroute, masculine, ‘pickled cabbage.’