A process is disclosed for producing an organic acid and optionally for simultaneously producing an ester of the organic acid. The process comprises the steps of: (a) combining an aqueous diluent, an ammonium salt of an organic acid, and an alcohol, thereby forming a homogeneous liquid feed mixture; (b) rapidly heating the feed mixture at a pressure sufficient to suppress at least some vaporization of the alcohol and holding it at a temperature and for a time sufficient to decompose the ammonium salt of the organic acid into ammonia and free organic acid while rapidly removing the ammonia from the reaction-mass transfer equipment, and optionally to react at least some of the free organic acid with the alcohol to form an ester of the organic acid, thereby producing (i) a vapor product stream that comprises ammonia, water, and alcohol, and (ii) a liquid product stream that comprises free organic acid, optionally ester, and alcohol, where of the total quantity of alcohol in the vapor product stream and the liquid product stream, at least about 10% by weight is present in the liquid product stream; and (c) recovering the free organic acid and optionally the ester from the liquid product stream. The liquid feed mixture can comprise a concentrated crude or partially purified broth produced by a fermentation process.