What is reflux and how does it influence Scotch whisky character?
Reflux is a physical process that occurs inside the still during the distillation process.
As a liquid boils various compounds are vaporised and turn into a gas. These gases start to rise up the still, and if they reach the condenser they turn back into a liquid and are collected as distillate.
However, a compound will cool down (or lose energy) as it rises in the still. If it condenses back into a liquid while in the still, it will drop back down into the pot to be boiled again. This is reflux and the process amounts to a progressive refining, purifying action which develops sophistication of the resultant distillate, eliminating impurities and other baser, oilier elements.
The amount of reflux activity within a still massively affects the spirit character. More reflux leads to a lighter and more refined new make spirit, while less reflux leads to a heavier, oilier and denser new make spirit.
The following factors can all increase or decrease reflux and therefore affect the spirit character:
- Still size
- Still shape
- Charge volume
- Slope of the lyne arm
You can learn more about reflux and the factors which influence it in the Batch Distillation module of the Certificate in Scotch Whisky. You can try the course out for free and access a varied selection of interactive lessons at the click of a button. You don’t need your credit card and there’s no obligation to buy. Simply see for yourself the wealth of knowledge available, how the platform feels to use and so on.
