What are the differents between pot still, coloum still and alembic still...?

Question

Process of making spirit

Answer 1

Pot stills and alembic stills are essentially the same thing.
They're basically a pot containing a fermented wash (grain for whisky, grape for brandy, molasses for rum, etc.) that contains a small percentage of alcohol. The pot has a cap on it with a tube leading out to a condenser. As the wash in the pot is heated, the mixture of alcohol and water turn to vapor, rise up through the cap, through the tube in the cap and through the condenser where the concentrated alcohol/water vapor turns back into a liquid and collected.

A column still takes the same vapor from the boiler and instead of directing the vapor straight to the condenser, it carries it through a set of perforated plates. At each plate, the vapor partially condenses where the heavier compounds (water and heavier alcohols) condense first and allow the alcohol and lighter compounds to stay vaporized and continue rising. The more plates, the purer the alcohol becomes as it goes through them. The accumulation of the partially condensed liquids trickles back down to the previous plates and eventually to the boiler. What this does is that it acts like a pot still for every plate, so it's like redistilling multiple times in one shot.

A column still makes purer spirits than a pot or alembic still, but at the cost of flavor, too. Some of the heavier components distilled away are those that contribute flavors. That's why lighter rums, neutral spirits, inexpensive whiskies, and such are distilled with column stills. Scotch Whisky is still made with pot stills, and typically only distilled twice, so they retain a large portion of the flavors of the malts used. Strongly flavored rums also use pot stills.