Wiktionary
n. a still used for distillation in the production of whisky; a still used for crude separations in chemical plant.
Wikipedia
A pot still is a type of still used in distilling spirits such as whisky or brandy. Heat is applied directly to the pot containing the wash (for whisky) or wine (for brandy). This is called a batch distillation (as opposed to a continuous distillation).
At standard atmospheric pressure, alcohol boils at 78 °C (172 °F), while water boils at 100 °C (212 °F). During distillation, the vapour contains more alcohol than the liquid. When the vapours are condensed, the resulting liquid contains a higher concentration of alcohol. In the pot still, the alcohol and water vapour combine with esters and flow from the still through the condensing coil. There they condense into the first distillation liquid, the so-called "low wines". The low wines have a strength of about 25–35% alcohol by volume, and flow into a second still. It is then distilled a second time to produce the colourless spirit, collected at about 70% alcohol by volume. Colour is added through maturation in an oak aging barrel, and develops over time.
The modern pot still is a descendant of the alembic, an earlier distillation device.
The largest pot still in the world was in the Midleton Distillery constructed in 1825, County Cork Ireland. It had a capacity of and is no longer in use.
Components of a traditional pot still:
- Boiling Chamber – Where the mash is heated
- Lyne Arm – Transfers the steam to the condenser
- Condenser – Cools the steam
Image:Cognac_pot_still_DSC04032.JPG|a Cognac pot still Image:Whisky safe DSC05276.JPG|a spirit safe (i.e. padlocked apparatus at the end of the pot still enabling the distiller to cut off the "heads" and "tails" of distillation; it is padlocked for excise reasons)
Usage examples of "pot still".
There it was: an old pot still, an almost cartoonlike relic from a vanished era, with an enormous copper cauldron sitting on a tripod stand and the ashes of an old fire underneath.
Her glance went to the small fire of twigs outside, where a pot still simmered.
Somewhere down there, Carlos knows, is the place where the original pot still resides, buried in billowing drifts of green which would be invisible to all those who don't believe in the plant's power.
Jamie said, ruefully poking at the makeshift pot still at the edge of the small clearing.
Then Pinch sniffed, noticing the klah pot still in Tagetarl's hand.
Then, flinging off his cloak on to a bench, he went to the porridge-pot still hanging by the fire, dipped up some with the ladle, thick and stiff after the night by the hearth, and began to munch on the heavy stuff from his fingers.