A column still, also known as a continuous still or Coffey still, is the most efficient type of still. It is preferred for its ability to continuously distill and yield spirit with higher alcohol content. A column still consists of two large columns. In the first, mash is added towards the top of the still where it falls to the heated bottom. There the heat vaporizes the liquid and forces the alcohol and other molecules to the top (these are the components that boil at a lower temperature than water, so they vaporize first). These vapors pass through a series of plates on their way up the still, each time condensing back to a liquid state before vaporizing again. With each pass of a plate, more and more congeners are whisked away and a higher concentration of ethanol makes its way up to the next plate. In the second column, these vapors are cooled and condensed back into liquid form. Often the process with be completed two or three times making for a very clean spirit.

Spirits produced in a column still can differ greatly from those produced in a pot still. Because of a column still's ability to remove impurities and congeners so effectively, spirits can often lack in character compared to those produced in pot stills. That's not to say that column still produced spirits are all characterless, bourbon whiskey is most often produced in a column still and is often packed with flavor and nuance. (Spirits/Production)