Provided is a method for producing an ester of butyric acid from an acid mixture, comprising contacting an aqueous carboxylic acid mixture comprising butyric acid and at least one additional carboxylic acid selected from the group consisting of formic acid, acetic acid, propionic acid, lactic acid, hydroxybutyric acid and combinations thereof, wherein at least 30% of the total amount of acids in the aqueous carboxylic acid mixture are in free acid form, with a liquid extractant having a Hildebrand solubility parameter of less than 25 MPa(1/2); separating a resultant butyric acid-comprising extract from a residual aqueous phase; contacting a resultant separated butyric acid-comprising extract with an alkanol in the presence of an acid catalyst, to form a product comprising an ester of butyric acid and alkanol and optionally water; wherein when water is formed, separating water to provide a separated product comprising an ester of butyric acid.