WordNet (r) 3.0 (2006):

vinegarish
    adj 1: tasting or smelling like vinegar [syn: acetose,
           acetous, vinegary, vinegarish]
    2: having a sour disposition; ill-tempered [syn: vinegary,
       vinegarish]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "vinegarish":
   acerb, acerbate, acerbic, acescent, bearish, bilious, bitter,
   cankered, choleric, crab, crabbed, cranky, cross-grained,
   crotchety, dry, dyspeptic, embittered, green, jaundiced, ornery,
   pickled, pungent, sec, sour, sour as vinegar, sour-tempered,
   soured, sourish, tart, tartish, unripe, unsweet, unsweetened,
   vinegary, waspish