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View Full Version : Vacuum Distillation under $5k?



Komma
10-23-2014, 08:12 PM
I was just told I could use vacuum distillation to lower the ABV in my beer. The description was simple: get a glycol dairy tank about 30-50 gallons. Pour in your beer. Vacuum distill while pumping hot glycol into the jacket. And in no time I can run the ethanol out into the drain. Then I would add this beer back into my brite, remove another sample and repeat until the ABV is where I want it.

So I Google vacuum distillation systems and, wow, these things are not cheap.

Advice on where to find a small system as described?

jebzter
10-24-2014, 09:00 AM
To get the EtOH out at 25C, you would have to reduce the pressure in the tank to less than 10kPa which is more than 13psi less than atmospheric pressure. Im not sure how much negative pressure your tanks are rated for, so I would check that unless you want to implode the tank. So you would have to go warmer to keep the vacuum pressures lower, and I think there is a large risk of oxidation when heating the beer and transferring it. The other issue that I see with this is removal of other volatile compounds. Essential oils from hops and other flavor compounds are even more easily boiled off than the EtOH, these would get removed at the same time. I'm not sure that this is the best method for EtOH removal, plus you would need a pretty good sized pump to maintain vacuum on a big tank. That said, you can convert an air compressor or refrigeration compressor to create up to 27inHg of vacuum pretty easily.

wildcrafter
11-05-2014, 05:40 AM
Here's a new method to try? Pervaporation.
http://www.eurekalert.org/pub_releases/2014-11/f-sf-itt110414.php