This blog provides information for educational purposes only. Read our complete summary for more info.

Kyle Brown

Owner of Clawhammer Supply

Increase Final Proof by Packing Still Column

Copper Mesh, Raschig Rings, and Glass Beads

Packing a distillation column with copper scrubbers, raschig rings, or glass distilling beads is the easiest way for a commercial distiller to increase the final proof of distilled alcohol. The packing material increases final proof by causing a slight natural reflux action in the column. Commercial distillers will find that this also makes a better tasting product. If copper packing material is used, it simultaneously removes sulfur compounds from the vapor.

As vapor moves up through the column it migrates through a network of material that is a slightly lower temperature than the boiler, etc. For example copper mesh forms a thermal bridge between the cooler edges of the column and the center of the column (because it's super conductive). It creates an abundance of surface area that is just slightly below the condensing temperature of water (but ideally above the condensing temp of alcohol), providing opportunity for water vapor to turn back into a liquid while allowing the alcohol vapor to move on.  

As water comes into contact with the packing / mesh material, some of it condenses and drips back down through the column. However, alcohol vapor moves onward due to its lower boiling temperature and ends up making its way all the way to a commercial distiller's collection vessel. As a result, final proof is much higher than it would have been without the use of packing.

Pot Still vs. Pot With Thumper vs. Packed Column vs. Reflux

Thre are a lot of different still designs out there. Clawhammer stills are essentially simple pot stills with the addition of a column to make the design more versatile. If nothing is done to the column, our stills will operate just like a pot still and first run proof will start in the range of 100-110 proof and drop from there. If the column is packed, our stills will operate like pot stills with a "thumper" and first run proof will start as high as 130-150 depending on starting ABV. A true reflux still would require the addition of a dephlegmator.

Copper: The Best Column Packing Material

An added advantage of using copper scrubbers as column packing material is that they remove sulfides from the distillate. Sulfides are found in some fruits and are also a natural byproduct of the fermentation process. They tend to get concentrated when products are distilled. This will show up as off flavors and smells in the final product. The best way to get rid of it is to add as much copper to the still as possible.

Sulfur compounds react with copper, and are precipitated out of liquid and vapor during the distillation process. If you're a commercial distiller who wants to make top shelf spirits, sulphur absolutely needs to be removed during distillation. For example, Downslope Distilling in Denver, Colorado uses a 240 gallon, 100% copper still with two large diamond shaped chambers in a column formation made by Col. Vaughn Wilson of Arkansas. The chambers contain trays that are loaded with copper mesh. Downslope's head distiller insists that this is one of the reasons that their whiskey is so good (and they have the medals to prove it). So, even if a commercial distiller isn't using a column still, it's not a bad idea to add as much copper to it as possible. Accordingly, we believe that using copper mesh or copper scrubbers is the best way to pack a column. 

Here's how to pack the column on Clawhammer's Copper Stills:

• Add 1-2 scrubbers to column of a 1 gallon still.
• Add 4-8 scrubbers to the column of a 5 gallon still.
• Add 5-10 scrubbers to the column of an 8 gallon still.
• Add 7-13 scrubbers to the column of a 10 gallon still.

Note: A distiller MUST make sure that packing material is 99.9% copper - which can be hard to find. To make it easy we've sourced pure copper scrubbers and have them available here for purchase. DO NOT buy copper mesh or scrubbers if the product does not explicitly state, or if it cannot be verified, that they are pure copper. Some copper mesh / scrubbers contain other metals while other products are copper coated steel. Also, if copper scrubbers are purchased, remove steel clasp in center of scrubber.

Other Packing Material: Glass Beads and Raschig Rings

Packing a column with glass beads or raschig rings is not optimal for several reasons. First, they don't remove sulfides. This is actually a big strike against both of the materials. Removing sulfides is critically important for a commercial distiller when crafting top notch spirits. Second, they're difficult to install and secure in the column. Third, (this applies to glass beads only) actual scientific glass distillers beads are significantly more expensive than the other materials. The cost alone makes this option a no-go.

How to Install Copper Scrubbers / Mesh

Installing copper packing material in the column is very easy. First, the material goes in the column (not the boiler, not the condenser, etc.). If a distiller is using scrubbers (after removing steel clasp that holds scrubber together) simply push the scrubbers up into the column. The more the better, but do not use force to install them. They should fit in the column loosely and there may even be a tiny bit of space between them. Scrubbers will need to be unraveled before being installed in a 1 gallon kit. Though, they fit very nicely in the 5 and 10 gallon columns.

Where to Buy Copper Scrubbers / Mesh for Columns

Pure copper scrubbers are available on our website. Click on the picture BELOW to purchase. Note: we do NOT recommend, nor do we have a good source for raschig rings or glass beads.