Reflux Still For Small-Scale ETOH Reproofing

There are quite a few threads here relating to ethanol recovery, but not many I could find that related to remediating the inevitable water contamination most ethanol extractors will experience at one point or another with their expensive hydrophilic solvent. So I figured I’d start a thread for those who are looking to reproof their ethanol via reflux distillation to discuss different builds and designs for getting our ethanol proof to that magic 190. As a disclaimer, I’m definitely no expert and know there are quite a few members here who have much more experience in still building than myself. I just figured I’d open the conversation and hopefully get those individuals to join in with their tips and recommendations.

My own current build is not very fast, but it gets the job done. It is a liquid-managed (LM) inline “Bok” design, which means my reflux ratio is controlled by my takeoff rate. This takeoff rate varies greatly depending largely on the surface area of the packing. The surface area of the packing mostly depends on the packing material used (marbles, pot scrubbers, plates, etc.), the diameter of the column, and the height of the column. Other designs which I am not nearly as familiar with are vapor-managed (VM) and coolant-managed (CM) stills. This link sums up their differences nicely.

As I mentioned earlier, the design I am most familiar with and is supposedly easiest to build would be the LM inline Boka. It’s been years since I built it and it definitely needs some upgrades, but I think I only spent around $300 on the entire build. The links I’ll provide below are detailed design plans and operating instructions for such a design.


Here are some pics of my own build. She’s dressed in rags (fiberglass insulation and masking tape) right now since I kind of ghetto-rigged the insulation after an incident years ago stripped her naked from her much nicer insulation, but she still runs great. Insulating the column is recommended as it will make it much easier to achieve and maintain a proper reflux ratio.

We just started carrying Ethanol drying mol sieve that we lovingly call Proof Up Beads. They hold about 20% their weight in water. Reflux to 180-190 and the sieve up to 195.


That’s actually not a bad way to go about it. With my setup, I can produce 180 about 1L per hour faster than I can 190.

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Very nice!

Could a person buy a decent 2" reflux still from eBay and expect decent results?

I’m wondering if a yeast brink keg with a water heater element in the bottom controlled with a distillation temp controller and a 2" or 3" reflex condenser would work ok.

That should work! Buyer beware on ebay though, as I have seen quite a few “reflux” columns for sale that were nothing more than tall pot still heads. If it doesn’t have a valve, you probably can’t make azeo with it.

Ahh, that’s a coolant managed still. I suppose the valve would be the gate valve on your hose or another inline valve. I have zero experience with that packing or style of still, so I couldn’t tell you how fast it would be, but it looks like it would definitely work. Sure is a beautiful piece.

We use a 8 gallon still with four flutes and a brazed plate heat exchanger. The heating element is 5400w that’s good for around 300 ml a minute without a vacuum and a round a liter a minute under a moderate vacuum.

If you keep the temps under 120f under around 20 inches you can get 190 on a single pass.


Are you running the heater element IN the ethanol?

That’s standard for low wines, but seems less than ideal if reproofing 150 (for instance).

Yes, directly submerged electric element. You need a proper controller to cycle the hz to the elements to keep from over heating the alcohol. Keeping the temperature low keeps the element at less than 40% power and results in a very selective distillation.

I also decarb in this same rig with great results.

This allows me to extract, winterize to -50f, filter, recover and decarb completely inline. I can now have distilant ready crude in a few hours after the completion of the extraction cycle.


sweet setup


I had no idea that kind of output was possible with that small a column. I heard flutes were awesome but damn. What brand is that column? Or is it home built?

My 3"x48" reflux column packed with SPP. Runs about 4L per hour Azeo. Built with parts from Glaciertanks and StillDragon (all but the Borosilicate).


It’s a 8 gallon still with a 5400w element. The real performance comes from the brazed plate heat exchanger. We run a open water circuit with a slow bleed and it flows constantly at 45f. I could run at least 20k watts of heat for one brazed plate heat exchanger.


that is a thing of beauty!
thank you for sharing.


Hey, thanks for sharing your set up!

Is the insulated cylinder up on the wall a condenser or a filter ?

And the two smaller black units screwed to the plywood?

I was just going to post mile hi. I love their stuff. Do you use your heat exchanger for cooling?

Beautiful setup. Do you find that the glass provides adequate insulation of the column? I guess I’ve only ever run my rig outdoors, but I noticed improved consistency after I insulated my column. But then again, my column is copper.

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Thanks! The glass is definitely adequate. Keeps a nice gradient through the column. When I ran a stainless column, I did insulate it though.