|The traditional still is called the 'Pot Still'. In simple terms, it is an enclosed kettle which narrows towards the top to collect vapor driven off by boiling the contents. A downward pipe (the neck) from the head of the still carries the vapor through cold water which causes it to condense and run into a receiving container.
Pot Stills are made from copper which was - and is - the best material because it scavenges certain impurities out of the alcohol.
- Improvements have been made since the earliest days of the crude alembics and pots, but it is still a laborious procedure loading up, boiling off, emptying dregs and recharging for the next run.
- Pot Stills can only distil one batch at a time.
- The Pot Still is not as efficient as the Continuous Still, but tends to produce a much more flavorful product.
How does it work:
First, the pot still is filled with a mildly alcoholic product, normally in the range of 5-9% alcohol by volume (ABV). The still is then slowly heated from below. This used to be done by open fires but now is most often done by gas, electricity and/or steam. The alcohol starts to turn into vapor around the aforementioned temperature of 78’C, and begins to rise in its vaporized form into the Swan’s Neck. The bottom of the neck is immersed in cold water, which cools the vapor back into liquid form. This liquid that now flows out is approximately 20%ABV and which we shall call ‘low wines’.
After the low wines have been collected they are moved into another still that is generally smaller, and are distilled for a second time with a slight difference: The second distillation is divided into three parts. The first part is the ’heads’, the second is known as the ’cut’, and the last is known as the ’tails’.
The heads and the tails both contain undesirable flavors, and are therefore separated from the cut and thrown right in with the next batch. The master distiller decides when the heads finish flowing and the desired cut begins. He must also decide when the cut has ended and the tails have started to come out of the still. This time the spirit will flow out of the still at approximately 60%ABV. Sometimes the spirit will be distilled a third time, this is a practice that the Irish whiskey makers are very fond of as it makes a lighter, cleaner spirit with less impurities (these “impurities” however also add taste to the spirit).
A picture of a basic pot still example: These are pictures of an original 1920's American copper pot still, which was for sale on Ebay.com in 2002. This is a true classic set up of a pot still used by moonshiners & home distillers. Next to it, a picture of modern potstills as being used still today in distilleries of Scotland and all over the world.
In the distilling industry, a pot still set up is mostly used in distilleries which produce grain based beverages such as Whiskey, Bourbon, Jenever, Gin etc. In an industrial environment, the production scheme would look as follows: