Put simply there are two types of stills for the distillation of spirit.
Commonly used in production of Cognac and Single malt, little has changed with this still for centuries. Consiting of a vessel, to which heat is applied, as the contents boil the vapours are collected and condensed in another vessel. Because alcohol boils at a lower temperature than water, the vapour collected has a higher concentration of alcohol.
Patented by Aeneas Coffey in 1831, the Column Still runs continuously, instead of batches. It operates like a series of pot stills, in the form or porous layers in a vertical tube. The vapour rises, and portions condense as each layer gets cooler.
Column stills can produce a spirit of 96%, whilst a Pot Still man only reach 40-50% and may require additional distillations.
Column Still distillate is clean and pure, but lacks the rich oils nots of Pot Still distillate.