Types of Stills

Whats the difference between a pot still, reflux still, and fractionating column ?

A POT still simply collects and condenses the alcohol vapours that come off the boiling mash. This will result in an alcohol at about 40-60% purity, with plenty of flavour in it. If this distillate were put through the pot still again, it would increase in purity to around 70-85% purity, and lose a bit of its flavour.

Examples of Pot Stills

A REFLUX still does these multiple distillations in one single go, by having some packing in a column between the condensor & the pot, and allowing some of the vapour to condense and trickle back down through the packing. This "reflux" of liquid helps clean the rising vapour and increase the % purity. The taller the packed column, and the more reflux liquid, the purer the product will be. The advantage of doing this is that it will result in a clean vodka, with little flavour to it - ideal for mixing with flavours etc.

Examples of Reflux Stills

A FRACTIONATING column is a pure form of the reflux still. It will condense all or most of the vapour at the top of the packing, and return about 9/10 back down the column. The column will be quite tall - say 600-1200mm (2-4 foot), and packed with a material high in surface area, but which takes up little space (pot scrubbers are good for this). It will result in an alcohol 95%+ pure (the theoretical limit without using a vacuum is 95.6%), with no other tastes or impurities in it. Note that both reflux and fractionating stills can still be used to make whisky, rum etc, as they allow a very precise "cut" between the heads, middle, and tail runs.

Examples of Fractionating Columns
