What is column still distillations? Read further.
The column still distillation has been in the world for almost two
centuries now. The column still distillation units take their inspiration from the Irish distiller Aeneas Coffey’s invention.
However, the stills today have undergone a countless number of interactions. The column still distillation produces everything from whiskey and vodka and anything that lies in the middle.
What’s so special about column stills anyway? Well, they can produce your favorite spirit round-the-clock without having to stop for cleaning.
They sound interesting, don’t they? Also, there is a significant difference between column still and pot still. All excited? In today’s post, we’ll discuss everything and anything you need to know about column stills.
Let’s raise our glasses as we explore column stills and how they work!
What Is A Distillation Column?
Column stills came into existence around the 19 th century. The distillation column takes a cue from Scottish, Irish, and French distillers.
The goal of the distillation column is primarily to offer a more efficient distilling system. These distillation columns aim for higher quality, more quantity, and a shorter span of production.
One of the early pioneers of the distillation column is the Scotsman, Robert Stein. He developed a continuous distillation process and patented it.
True to their name, the continuous distillation stills operates constantly. On one side, fermented wash enters the column frequently, and from the other side, there’s a steady
supply of fresh spirit.
What goes on inside the distillation column is the pure beauty of a fascinating engineering design. The distillation columns are large structures that carry heated, flammable liquids.
They consist of several components to complete the distillation process.
Construction of the column still
These components enhance material transfer or transfer heat energy. You’ll find the following parts in the distillation column:
- Internal parts such as plates, or trays, or packing can enhance the component separation.
- A sizeable vertical shell. It is where the process of separation of the liquids takes place.
- A reboiler to allow essential vaporization for the distillation process.
- A condenser that cools and condenses the vapor that the top of the column emits.
- A reflux drum to contain the condensed vapor from the column’s top. This drum can recycle the liquid back to the compartments.
It is the vertical shell that contains the column internals. Together with the condenser and reboiler, the vertical shell constitutes the distillation column.
The number of columns will differ from one spirit to another. For instance, a single column can produce bourbon, wine, and more.
However, for vodka, four or five interlinked columns are essential. It is because vodka requires a high level of separation.
How Does Column Still Distillation Work?
Now that you know “what is a distillation column?” you might be curious how they work. Have you seen how a puddle of water evaporates in the hot sun?
The whole idea of the column still distillation is based on the same principle. Imagine a tall vertical column stacked with a pot still upon another pot still and then another pot still.
You can read more about pot still here.
The column still distillation units have perforated plates or partitions. These partitions make up different chambers in the column still.
The mash enters through the top portion of the column still and starts to sink immediately. At this point, the mash has minimum alcohol content like wine or beer. Read more about how to make moonshine.
Throughout the process, the bottom of the still is hot. The process involves allowing steam into the still’s bottom and letting it rise substantially.
The column’s top is the coolest part. It is why when the mash enters through the top, it sinks. When the spirit interacts with the steam, the heat vaporizes that mash.
As a result, it pushes the volatile molecules and alcohol to the top of the still. Whenever the vapor hits the still’s plates, they begin to recondense. During the condensation process, the heavier molecules stay behind.
As the vapors pass through different columns, they shed everything that is not ethanol. You’ll be surprised to know that the column stills can distill 95% ABV or 190s.
However, liquids like brandy, bourbon, and many others can’t distill at high proofs. For example, by law, bourbon is not feasible to be clarified at more than 160 proof.
When the process is nearing an end, the unit directs the alcohol out of the still’s top. The condenser stores this alcohol, where it condenses into liquid again.
With a few spirits, they might need redistilling at least once. It can be in a pot still or maybe in some other column. For instance, gin and vodka are cut with water and then bottled up.
Brandies and whiskies go into large barrels for aging.
Differences With Pot Still
The fundamental processes in the pot still and column still are much the same. However, they differ from each other on various grounds. In this section of the post, you’ll understand how the column distills from the pot stills. Take a look:
As their name suggests, the pot stills look like pots. They have a spherical chamber, a protruding lyne arm, and a swan neck. The component of the still attaches itself to a coiled condenser and the collection vessel.
On the other hand, the column stills have a more industrial-style design. They are vertically taller than the pot stills and have multiple chambers stacking on top of each other.
Sometimes, the column chambers can be several stories high. Also, column stills can use a combination of copper or stainless steel for their structure. But, the pots stills are mostly made of copper.
Pot stills are an ideal method for producing more flavored distillates. These stills can have various alcohols like cognac, mescal, rhum agricole, single malt scotch, and more.
On the other hand, a column still is a suitable process for neutral spirits. Most alcohol manufacturers use it for vodka and gin. The column units allow various separation levels for vodka and gin.
Pros & Cons
One way where the column still has the edge over the pot ones is the efficiency. You already know that columns stills deliver continuous distillation.
The uninterrupted distillation process allows them to have an enormously higher production capacity than pots.
Moreover, the column stills do not require cleaning after the preparation of every batch. The continuous stills offer a cleaner and purer distillate than the pot units.
However, the pots are renowned for producing more congener-rich and flavorsome spirits. The columns have an ABV capability of about 96%.
In the case of pot stills, they can reach a maximum of 60-80% ABV.
Copper Role In Column Still Distillation
It is not mandatory that columns still distillation units have copper as their primary material. The stills might use a mix of copper, only copper, or only stainless steel.
You might also come across a stainless steel column distillation unit with internal copper elements. So, what is the purpose of copper?
Copper slashes out a significant amount of sulfur from the distillate. In the fermentation process, sulfur is a typical component that arises naturally.
The manufacturers remove sulfur as it lends a bitter or sour taste to the spirits. For the sake of quality, manufacturers find it best to eliminate it.
The sulfur and copper react together to create copper sulfate. This copper sulfate separates from the liquid. As a result, the bitter-sour taste of sulfur disappears from the end product.
Besides, copper also allows the column still to dissipate heat evenly. Because of all these features, the alcohol from the column still turns out to be better.
It is why most of the stills across the world use copper for their structure or internal components.
What Spirits Do They Produce?
Some people believe that column stills are incapable of producing crafty spirits. However, that statement holds no truth. Column still distillation is ideal for neutral-flavored alcohol.
The column still method is suitable for vodkas and whiskey blends. You’ll be surprised to know Johnnie Walker Blue and Pappy Van Winkle also use column distillation methods.
Many a time, white rum, brandy, and bourbon producers also use column still distillation. As we mentioned earlier, the method is more suitable for spirits that require aggressive separation.
Some of the best vodkas and gins around the world come from a column still.
Column still has many names – continuous stills, Coffey stills, and more. Hopefully, now you are all aware of the column still distillation.
When it comes to spirit production, columns still define an artful creation. The column still distillation method can produce a range of quality spirits.
However, it’ll still be a lifelong argument if it is better than pot stills and how. This piece also closely talks about the essential differences between the two.
The next time you find yourself in a debate of column still vs. pot still, you’ll have plenty to add. We hope that this article answered all your questions about column still distillation. Cheers!