Jamaican Style double retort pot still function/use information request.
I have done a bit of research into the double retort style pot stills used in Jamaica; Such as those used at Appletons Estate, Hampden Estate or Mount Gay Distillery etc.
I am unsure if I am allowed to post links so won't at this stage.
Perhaps those of you who have visited operating stills of this type (unfortunately I have not yet) could answer a few things that I have been pondering for far too long? Basically I am interested in an accurate account of the actual run of this type of still.
I understand the charging of low and high wines and ratios etc as this information is available and also the general process (I have owned and operated a number of stills of varied designs over the last 20 years here in NZ where this is perfectly legal as many will be aware of).
However I would like to know (as I have heard anecdotal accounts only) if these stills build much pressure, I can't see any pressure gauges on any pics or drawings (however the nature of the design and the sealed retorts suggest some pressure build-up)? I do note there are mushroom like appendages also seen in whiskey stills etc. that are sometimes referred to as 'anti-collapse valves' - does anyone have a drawing or schematics on how these work are setup?
Also do the liquid volumes of the charged retorts alter throughout the run, and if so, are these ever discharged to keep levels and pressure at/below certain levels by the distiller? From the pipework it appears that it would be possible to drain a retort back into the main pot still to reduce levels back. However in my experience one could also reduce heat input to the main pot still and not drive the system as hard. I have never heard of any accounts of this type of retort functioning like the old American style 'thumper' where the pressure and level would build and create the banging/thumping noise.
I am also interested in what type of diffuser end there might be on the pipe leading into each retort. Are these just cut flush or do they have holes drilled at the end to diffuse the incoming vapour charge throughout the high/low wine charge?
Also, does anyone know if Appleton's in particular uses dunder in there wash at all? It is a fairly common practise from the area but I've never heard of this distillery using it.
Sorry for the long convoluted question, but I am sure there are those with a reasonable knowledge of this on the forum (as I have long popped in and read but only recently signed up).