An Etymological Dictionary of the German Language/Bier
Bier, n., ‘beer,’ from the equiv. MidHG. bier, OHG. and OLG. bior, n., comp. Du. bier, AS. beór, E. beer, OIc. bjórr; Fr. bière is borrowed MidHG. bier. There can be no connection with Lat. bibo, Sans. píbâmi; nor can Gr. πίων, OInd. pîvas, ‘a rich drink,’ be cognate. It is rightly thought to be akin to an OTeut. term for ‘barley,’ OLG. and AS. beó (OIc. bygg), from Teut. *bewwo-, based on a pre-hist. *bhéwo-, while the cognates of Bier point to a deriv. *bhewro-. Thus Bier is equal to ‘barley-juice’?.