3. Condenser

A condenser is a device for re-condensing the alcohol vapour back into a liquid spirit upon leaving the still. There are two main types of condenser used at Scottish and Irish distilleries: ‘Shell and Tube’ condensers and ‘Worm Tub’ condensers (a third kind, common among American distillers, is the Dephlegmator). The type of condenser used by a distillery hugely effects the flavour of the whisky.

A shell and tube condenser consists of a long hollow cylinder filled with cold water, which contains a large number of copper pipes. When the alcohol vapor touches the cold pipes, it cools down and becomes liquid.

The worm tub is usually in a large tank or container with a cooling loop (worm) immersed in water. Worm tubs are the older more traditional method of re-condensing the distilled spirit. They were, and in some distilleries still are, large vats of cold water with a single, coiled copper tube, or ‘worm’. The worm is used to obtain a rich spirit character with as little copper contact as possible during slow re-condensing in the worm. Today Worm tubs are still in use at c.16 Scottish distilleries.