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| Richard Seale |
Our discussion on wooden vat stills helps
illustrate a key concept. Take away the lyne arm, retorts, plates and the
condenser and you are left with a vessel not a pot still. I think that is strikingly obvious in the case
of the vat still. It is the reflux
surfaces that define the distillation fundamentals of a pot still. Their shape,
position and material effects reflux and thus how the congeners will arrive.
Change the shape and the spirit changes. Their shape, position and material determine
their catalytic effect when made of copper.
Harrison et all (2011) found that even
when including the shoulder, the effect of copper in the pot section was
marginal. This part though above the liquid level will have little reflux
because it will be too hot. Little
reflux means little catalytic action. The wooden vat stills did use copper
shoulders which would ensure they lacked absolutely no important copper with
respect to an all copper still. Let me reiterate, the point of the
previous pot, the wooden vat still lacked for nothing in comparison to an all
copper still. That was the genius of the design.
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| Without the Copper, They are Just Pots |
Harrison et al (2011) found the copper in
all areas other than the pot section to have a significant effect on the spirit
with the copper in the wash still condenser to be the most important location
for copper. And to the possible positive
effect of the wood in the pot section of that sacred cow, I dared to answer,
only maybe. Yes, maybe. Because we do
not know the mechanism. It won’t be because of reflux, mainly because none
happens here. It won’t be because of a catalytic effect mainly because wood is
inert. It could be from another mechanism, it would likely be overwhelmed by
the potential variables in the lyne arm, retorts, condenser etc, but we are not
ruling the possibility out.
But most importantly however, we can’t be
sure the effect is preferred. Let me give an analog - it is well understood
that shell/tube condensers work "better" in that the catalytic effect
of the copper is better in a s/t condenser than in a worm tube condenser. But try to tell those who prefer the "meaty"
taste of the worm tub produced whiskies that it is better. So maybe is my answer.
