A worm tub condenser is a traditional piece of distilling equipment used in whisky production. It consists of a long, coiled copper pipe (the "worm") submerged in a large vat of cold water. As hot spirit vapor from the pot still travels down the coil, it cools and condenses back into liquid.

Because the vapor condenses more slowly and has less contact with the copper pipe, worm tubs result in a heavier, "meatier," and more complex spirit profile compared to modern condensers. While the vast majority of distilleries have replaced worm tubs with highly efficient shell-and-tube condensers, around 20 Scottish distilleries continue to use them to preserve the unique texture and flavor of their whisky..