Coffey Break

First thing’s first, neither caffeine nor coffee beans are involved in the making of a spirit with Coffey in the name or description. If that was where your mind went you are not alone. Enough people began shopping with that assumption that I decided to write this post.  

So, what does coffey mean?  

Let’s begin with how spirits are made. We start with a “mash” of a fruit or grain that has been fermented. For example, barley and water that has been fermented with yeast to create an alcoholic “beer”- if you will. To get whiskey, you must heat it up! This is done in a still so that you heat the mixture is allowed to boil and the ethanol (consumable alcohol) is separated from the rest of the liquid because ethanol boils at a lower temperature than water. The vapor must be cooled so that it condenses, and the liquid that is collected is a higher proof alcohol. Most spirits are distilled multiple times (usually twice, at least). 

Although there is evidence of distillation in many ancient cultures, the earliest clear evidence of distillation was in ninth century Iraq from Arab chemist, Al-Kindi.

Since then, Alembics, or apparatuses used for distillation, were developed over time. The most common and simple is the pot still, which looks like a kettle with a swan neck and an arm that acts like a spout where the vapor condenses into the collection vessel. 

Basic Pot Still - Credit: Black Creek Brewery

In the early 1800s, many European scientists, engineers, and businessmen contributed to developing all sorts of distillation apparatuses to make them more efficient. It was Irishman, Aeneas Coffey that patented and commercialized the first two-column still that provided a continuous distillation. A Coffey still runs continuously with multiple chambers stacked on top of each other. The mash (in our example of fermented barley) can be constantly added while the column continuously operates. As the mash enters near the top of the still, it flows downward and is heated by steam.

Pot Still Diagram

Once it’s heated enough to evaporate, that vapor rises through a series of plates. Each plate strips some of the vapor’s heavier compounds before it makes its way through the rectifier column where it is cooled, condensed and the spirit comes out. It’s a complex engineering system but the takeaway is that it saves time and labor since distillers don’t have to stop after each batch to clean the still. This method also produces a “purer” spirit, which depending on the distiller, may or may not be desirable.

Coffey Still Diagram - Credit: Gallo University

Bottom Line

Coffey Still

-Produces a “purer” flavored and neutral spirit since more compounds are stripped

-Capable of higher production levels

-Preferred for Gin, Vodka, White Rum and Brandy

Pot Still 

-More labor intensive as it must be cleaned after each use and requires more planning. 

-Produce more spirits with more flavor compounds- the good, the bad and the ugly!

-Preferred for Bourbons, single malt Scotch, Cognacs, Irish Whiskies such as Red Breast, Argricole Rhum.

Hybrid Situations…

There are some spirits, Bourbon being one with many examples, that can use both stills to bring the spirit to a higher alcohol level and to get the best of both worlds.

If you had told me when I was in high school that I would find anything chemistry related interesting, I would’ve laughed in your face.  But learning the science behind these beverages to understanding what is in my glass is thrilling to me. The world of stills is fascinating and complex. We hope this can be a building block for understanding how your favorite spirits are made.