Thanks for the link to the SWA (
One of the links from there had an interesting comment ...
"The Macallan" distillery ( http://www.themacallan-themalt.com
) state ...
The size and shape of the stills are crucially important. The more contact
the wash and low wines have with copper the better, since it acts as a
catalyst, removing sulphury impurities (in the wash still) and promoting
the creation of esters (in the spirit still) - effectively cleaning and
lightening the spirit. Small stills with a broad 'head' (the middle part of
the still), such as those at Macallan, are best of all: a narrow head tends
to increase the velocity of the ascending vapours and to reduce their
contact with the copper walls.
Finally, while we are on the question of still design, there is the
important matter of the length and angle of the 'lyne arm' - the pipe which
connects the top of the still, known as the 'swan neck' to the condenser.
Macallan's lyne arms are of average length, but they are acutely angled in
a downwards direction. This means that once vapours reach the neck of the
still they are more likely to go over and be condensed than to fall back as
reflux and be re-distilled. Again, the Macallan is unusual in this: most
distillers set out to increase reflux. But then, they may well not achieve
such copper contact (with its spirit-enhancing properties) as do Macallan's
Does anyone know anymore about this affect of copper ?