How the lyne arm on a still can affect Scotch whisky flavour

The lyne arm – the part of the still that joins the column and neck to the condenser system – has a big impact on reflux.

(Reflux – explained in this post – is a physical process that occurs inside the still during the distillation process.)

Specifically, it is the angle at which the lyne arm points towards the condenser that is of particular importance.

If it slopes upwards from the still to the top of the condensers, vapour will likely condense into liquid in the pipe and fall back down into the still, enhancing reflux. An ascending lyne arm – and therefore more reflux – typically makes for a light, refined and floral spirit character.

If it slopes downwards from the still, liquid generated will flow down into the condenser (rather than falling back into the pot), meaning there is less reflux. A descending lyne arm – and therefore less reflux – typically makes for a heavier, oilier spirit.

A straight lyne arm will not impact the character of the spirit with regards to reflux.

Studying the pot stills at a distillery and understanding how the slope of the lyne arm can affect flavour allows you to make an educated guess at the potential character of new make spirit coming off the still… test your theory on the final product.

You can learn more about all of this in the Batch Distillation module of the Certificate in Scotch Whisky.