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This article provides an overview of various types of distillers, including copper stills, stainless steel distillers, pot still, column stills, reflux stills, and more. Before we get started, a reminder: distilling alcohol is illegal without a federal fuel alcohol or distilled spirit plant permit as well as relevant state permits. Our distillation equipment is designed for legal uses only and the information in this article is for educational purposes only. Please read our complete legal summary for more information on the legalities of distillation.
Copper Pot Stills
Although pot stills were developed hundreds of years ago and their design is relatively simple, they're still commonly used today to produce a variety of products. For example, a simple copper still could be used to purify water, separate essential oils, concentrate fuel alcohol, and even produce spirits.
Traditionally, copper pot stills were commonly made using 100% copper. Originally, stills were likely made from copper because it was readily available, very malleable and easy to form, and conducts heat better than almost any other common metal. Today, stainless steel has gained popularity as a rival to copper in the distillation market. however, the tradition of copper continues. As you'll read below, copper has unique properties that make it an ideal material for distilling.
Copper Vs. Stainless Steel Distillation Equipment
After centuries of advancements in distillation and materials technology, why do some the best distilleries continue to use copper stills? And why do many essential oils producers also prefer copper stills? Years of trial and error by distillers as well as modern scientific testing has revealed that copper is actually beneficial to the distillate. Copper reacts with wash liquid and distillate vapor, removing the undesirable chemical compounds such as sulfur. This is vitally important to essential oils producers, who absolutely do not want their products to have a sulfur aroma. Also, seasoned commercial distillers will tell you that copper has a similarly beneficial effect on their products.
Clawhammer sells both copper and stainless stills. We manufacture a beautiful pre-built stainless steel still which has a lot of great features and distills wonderfully. However, many choose to add copper packing material to the column of our stainless stills to also take advantage of the benefits that copper provides.
Copper Pot Still Anatomy
To oversimplify, pot stills are comprised of a boiler, where liquid is heated and turned into vapor, and a condenser, where the vapor is turned back into a liquid. The oldest and most traditional stills include an ogee, swan neck, and lyne arm, in addition to the pot and condenser. The ogee directs vapor into the swan neck, the swan neck rises up from the boiler and directs vapor into the lyne arm, and the lyne arm carries vapor to the condenser. The shape and configuration of the swan neck and lyne will have a slight impact on the characteristic of the products produced with the still, but it won't be overwhelming.
Column Still / Reflux Still
A modern take on the traditional still design employs the use of a slightly more complicated and versatile still head. Modern pot stills utilize modular columns that can be configured to perform specific functions. These stills utilize a boiler that connects to a vapor cone, which directs vapor upward into a column. Columns may be left empty, allowing the still to be run like a traditional pot still. In this design vapor will move up through the column and then directly into a condenser. However, these stills may also be fitted with plates or other material that cause reflux and allow a commercial distiller or fuel alcohol producers to produce a higher proof product with fewer steps. Add a dephlegmator (described below) and the effect is amplified.
What is a reflux still?
A reflux still contains baffles, plates, scrubber, or packing material to cause partial condensation of alcohol vapors during distillation. For example, if a copper column still is equipped with simple copper scrubbers, some of the alcohol vapor will condense on the scrubbers as it moves up through them and will drip back down the column. Reflux action removes water from the alcohol vapor and allows a commercial distiller to increase the proof of the final product, thus eliminating the need to distill alcohol several times to increase proof.
Column Still Parts
The lower half of simple column stills very much resembles that of a pot still, and includes a copper pot and vapor cone. At the top of the vapor cone, alcohol vapor is directed into the bottom of a column. The column contains packing material or removable plates that allow for the condensation, redirection (down the column), and re-distillation of alcohol vapor and distillate. Plates are often simply flat perforated discs of copper. Alcohol vapor moves upward through the perforations. Some of the vapor will condense and some will move on. The condensed liquid builds up on top of the plates and liquid continues to bubble up through it. Once the liquid level above a plate is high enough, it will flow down a "downcomer," which is simply a pipe that allows liquid to overflow down to the plate below. There are many other plate designs, but this one is very common, very simple, and very effective.
For most applications, dephlegmators are not necessary. Many craft distilleries do not even employ the use of this technology. However for some applications, like making very high proof neutral grain spirits or fuel alcohol, they are useful.
A dephlegmator is sometimes incorporated into the top of a column still design. It is a device that works in a similar fashion to the copper packing and plates listed in the column still section above. However, there is one big difference. In the examples above, reflux is the result of passive or "natural cooling" caused by material temperature differentials between the boiler and the top of the column. A dephlegmator uses "active cooling" to force the condensation of vapor and induce reflux action.
Anatomy of a Dephlegmator
A dephlegmator is essentially an inline condenser built into the top of a distillation column. The dephlegmator can be as simple as a copper coil contained within the column. The coil would be hooked up to a cool water supply and water would be circulated through it (in a regulated fashion) to achieve the desired level of reflux. Dephlegmators can be as complicated as several pipes running through a water cooled jacket. Again, the flow of water would be regulated until the desired level of reflux is achieved.
A parrot is a device that allows commercial distillers and fuel alcohol producers use to measure the proof of alcohol that comes out of the still. Distillate drips out of a stills condenser into a collection cup at the top of the parrot. The alcohol flows down to the bottom of the parrot and then upward through the hydrometer chamber. A hydrometer is floated in the chamber and allows for easy reading of proof, as the still is producing alcohol. Parrots work like artesian wells, and the liquid product overflows out of the hydrometer chamber and then into it's final collection vessel. Checkout our article "How To Proof Alcohol" for more information on using a proofing parrot.