Abstract Recently Pontryagin's maximum principle has been applied to find the time-optimal reflux policy to achieve a given separation of two components by batch distillation. In the case where a sequence of identical charges is available, it is possible to improve upon this optimal policy by exploiting the extra degrees of freedom that result if a waste-cut is permitted. This is demonstrated with the aid of a specific example, using both piecewise constant and piecewise continuous reflux policies. Two methods of solution are discussed.