Mast distillation columns operate with feed temperature controlled to some fixed value at or close to the boiling point of the feed, variations in this temperature being seen as unwanted disturbances to the column. Conventional control schemes can meet top and bottom composition specifications within the scope of the column but at the price of long response times due to the considerable inventory of a column in relation to its throughput. This paper shows that by admitting the feed temperature as a control variable and using feed forward control, much faster responses can be achieved.