To reduce acetal and/or ester concentrations when separating ethanol from a crude product in one or more distillation column, at least one of the columns is operated at a higher pressure to increase the equilibrium constant that favors hydrolysis of the acetal. The crude product may comprise ethanol, acetaldehyde, water, ethyl acetate and one or more acetals, such as diethyl acetal. The acetal and/or ester concentration may be reduced thus reducing the need to separate acetal and/or ester from the crude product.