The Pioneering Power of Column Stills
When it comes to crafting fine distilled spirits, the choice of distillation equipment can make a huge difference in flavor and quality. While traditional malt whiskey distilleries exude a romantic allure, there’s an unsung hero in the world of spirits production – the towering and industrial-looking columns, often known as Column Stills or Coffey Stills. These imposing structures have quietly revolutionized the art of grain whiskey making and remain at the forefront of modern distillation techniques.
analyzer and rectifiers of a column still
Column Stills: The Backbone of Grain Spirits Production
These towering column stills may lack the picturesque charm of traditional distilleries, but their significance in the world of spirits cannot be overstated. Known by various names, including Column Stills, Coffey Stills, Patent Stills, or Continuous Stills, they are the heart of grain spirits production and high concentration of alcohol distillation.
The story begins in 1808 when the Frenchman Jean-Baptiste Cellier-Blumenthal introduced the first practical continuous distillation system. It was further refined in Scotland by Robert Stein and later optimized by the Irish-born Aeneas Coffey. These column stills consist of two interconnected parts, known as analyzers and rectifiers, each serving a specific function.
How Column Stills Work
The operation of these column stills is simple yet ingenious. The process begins with wash, the liquid to be distilled, flowing through a tube that snakes from the top to the bottom through the rectifier. Rising steam indirectly heats the wash, and it’s then pumped from above into the analyzer. Simultaneously, hot water vapor enters the analyzer from below and rises to the top.
Inside the analyzer column, horizontal perforated plates, or “perforated plates,” allow the water vapor to rise, while preventing the wash from dripping through. Instead, the hot liquid flows over each plate to the other side and cascades down to the next plate. As the rising steam contacts the wash, the alcohols, and other volatiles in it evaporate, while water and solids drip down and are collected at the bottom of the analyzer.
The hot alcoholic vapors are directed into the rectifier through a pipe system at the bottom. There, they continue to rise and condense due to the tube of the hot wash feed. The finest spirit is removed at a specific height in the rectifier, achieving the desired strength and quality. It is then cooled and collected in a tank. Meanwhile, heavier alcohol vapors can be reclaimed from the bottom of the column and returned to the analyzer’s upper part. The lighter alcohols leave the upper end of the rectifier with the steam and are also reintroduced into the steam circuit via a pipe system.
This continuous distillation system can yield distillates with an impressive alcohol content of up to 95% by volume. To preserve some aromas and flavors, grain whiskey is typically distilled with an alcohol content ranging between 70% and 80% by volume.
The birth of the continuous distillation process in column stills took place at Cameronbridge, the oldest and largest grain distillery in Scotland, founded in 1824. Today, column stills of varying sizes are used by many of the world’s top distillers, including major grain whiskey producers in the Scottish Lowlands, Irish distillers, and bourbon producers in the United States.
There is no denying that Column Stills have left their mark on the world of spirits production, enabling the creation of distillates with exceptional alcohol content and quality. While they may not possess the romantic charm of traditional pot stills, these impressive engineering marvels are the driving force behind the production of grain whiskeys, enriching the world of spirits with their remarkable capabilities. As we raise our glasses to savor the exquisite flavors and aromas of these fine spirits, let’s also raise a toast to the unsung heroes behind the scenes: those impressive column stills.
