An Etymological Dictionary of the German Language/Annotated/Traube
Traube, feminine, ‘grape, bunch of grapes,’ from the equivalent Middle High German trûbe, masculine and feminine, Old High German trûba (drûba), feminine, trûbo (druppo?), masculine; corresponding to Dutch druif. It is uncertain whether we have to assume Gothic *þrûba, ‘grape’ (Old Icelandic þrúga, ‘grape, winepress,’ is a derivative of Old Icelandic þrúga; see drücken).