by Joshua Evans on July 19, 2012
Alembic still is the earliest device used to extract alcohol, it’s said to be the ascendant of the modern pot still. It’s not surprising that the use of alembic stills has thrive until the modern distilling era, this is due to it’s effective functional design and craftsmanship.
Traditional alembic stills are made from copper, the metal that remains the best choice of both hobby and commercial distillers. The alembic design perfectly complements the several advantageous properties of copper in distilling alcohol.
The alembic has three basic parts namely, the retort pot, the onion head and swan neck and, the condenser and coil.
The lower part of the still, which is the retort pot, is responsible for firing/heating. The pot resembles a cauldron with a flat bottom to stand still on a heating surface (usually an electric stove or a hot plate). This is where the fermented mash is boiled until alcohol, due to its lower boiling point relative to water, vaporizes and moves up the onion top.
As the wash is heated, the steam naturally rises and swirls around the onion-shaped head that sits atop of the pot. The vapors then slowly go through the swan neck pipe (also called the lyne arm), the delivery tube that connects the still to the condenser. The lyne arm angle, diameter and material all have an effect in the final distillate. The angle determines how heavy (or light) the flavor of the whiskey will be while the diameter controls the amount of vapor that can swirl through the pipe. The material, being copper, helps speed up the moving vapors, eliminates undesirable chemicals produced during fermentation and also improves the flavor.
From the lyne arm, the vapors move to the worm or the coil that sits inside the condenser (with a top and a bottom fitting). You simply put the supply hose into the condenser (almost to the bottom) and use the top outlet to prevent overflow. The water-filled condenser cools the alcohol vapors and turns it back into liquid, which then drips off through the bottom nozzle of the condenser.
Some alembics are riveted (not soldered) and you may notice a "greenish paste" applied to the interior of the seams. This is a paste made from linseed oil and gypsum powder, a traditional way of sealing clearance stills. This will not affect the distillation process and the quality of your spirit.