In one embodiment, the invention is to a process for purifying a crude ethanol product. The process comprises the step of hydrogenating acetic acid in a first reaction zone in the presence of a first catalyst to form the crude ethanol product comprising ethanol, acetaldehyde, acetic acid, water, and acetal. The process further comprises the step of separating at least a portion of the crude ethanol product into a refined ethanol stream and a by-product stream. The refined ethanol stream comprises ethanol and acetaldehyde; and the by-product stream comprises acetic acid and a substantial portion of the water from the crude ethanol product. The process further comprises the step of hydrolyzing in a second reaction zone at least a portion of the acetal.