The lyne arm is a copper tube that connects the head of a pot still to the condenser. As it leaves the head of the still a lyne arm either angles upwards, is horizontal, or angles downwards. The angle of the lyne arm can have an impact on the flavour of the spirit and the speed and efficiency of the process and is a point of note that many a whisky anorak have mused over.
With an upward angled lyne arm, more reflux is created making the vapour work harder to reach the condenser which will help to create a lighter spirit. By contrast a downward sloping lyne arm reduces reflux and instead encourages ‘carryover’, where the heavier oils are more likely to trickle down towards the condenser, helping to create a heavier spirit.