They did have words for it, however. Greek brytos, used in reference to Thracian or Phrygian brews, was related to Old English breowan “brew;” Latin zythum is from Greek zythos, first used of Egyptian beer and treated as an Egyptian word but perhaps truly Greek and related to zyme “leaven.” French bière is from Germanic. Spanish cerveza is from Latin cervesia “beer,” perhaps related to Latin cremor “thick broth.”
Old Church Slavonic pivo, source of the general Slavic word for “beer,” is originally “a drink” (cf. Old Church Slavonic piti “drink”). French bière is a 16c. borrowing from German. U.S. slang beer goggles, through which every potential romantic partner looks desirable, is from 1986.