Vapour flows upwards in the rectifying column and condenses at the top.

The batch rectifier consists of a pot (or reboiler), rectifying column, a condenser, some means of splitting off a portion of the condensed vapour (distillate) as reflux, and one or more receivers.

The copper pot stills were aluminium coated, and used rectifying columns instead of swan necks to have greater control over the distillation process, and production switched from a triple distillation to a double distillation technique.

The distillery produced three different kinds of whisky, which was made possible through the rectifying columns on the stills: a heavily peated variety under the name "Dumbuck", a full bodied whisky named "Dunglas" and a light traditional lowland whisky under its own name "Littlemill".