Vacuum Distillation

[AndyInOregon]

Have any of you tried it?

I thought I had this great idea, vacuum distillation, where you can distill cold or warm, not hot, using low pressure instead of heat to vaporize the ethanol. After some searches I found out that some home brewers in Iceland do it, and a couple of commercial distillers in the USA do it. The taste of the end product is different because it's not heated, or not as much.

I don't have much experience homebrewing, and I haven't tried it.

 

[AndyInOregon]

Edit:

Unfortunately you need a NYT account to read this
https://www.nytimes.com/2009/12/02/dining/02curious.html

 

[hawkwing]

I imagine you’d need a special vacuum pump for that.

 

[passedpawn]

@clearwaterbrewer

 

[AndyInOregon]

I imagine you’d need a special vacuum pump for that.

You would want a diaphragm pump or some other kind that doesn't have oil in the vapor flow line.

 

[doug293cz]

Do you have references for any distilleries using vacuum distillation for primary ethanol concentration, and not just for low heat flavor infusions?

Brew on

 

[AndyInOregon]

Do you have references for any distilleries using vacuum distillation for primary ethanol concentration, and not just for low heat flavor infusions?

Brew on

Oops. Editing previous post

 

[AndyInOregon]

Do you have references for any distilleries using vacuum distillation for primary ethanol concentration, and not just for low heat flavor infusions?

Brew on

Here's a Japanese distiller that uses it

https://nankaishochu.com/2019/08/what-is-vacuum-distillation/

 

[bracconiere]

at that point i think looking into industrial chemical ethanol would be better? the heat is what carries over the flavors of the feed stock....why most hobby distillers prefer pot stills, over reflux, when you're trying to make good booze you're not trying to necessarily draw off ethanol at the azetrope level...

 

[AndyInOregon]

at that point i think looking into industrial chemical ethanol would be better? the heat is what carries over the flavors of the feed stock....why most hobby distillers prefer pot stills, over reflux, when you're trying to make good booze you're not trying to necessarily draw off ethanol at the azetrope level...

You may be right. The distillers that do it claim a flavor advantage. But of course they would.

 

[bracconiere]

You may be right. The distillers that do it claim a flavor advantage. But of course they would.

well try a test batch i think you'd need stuff like this...

https://www.ebay.com/itm/2831144135...bDG7Xd/7LIouY8HRDIBSMxG7CfiM|tkp:BFBMiOyS4Mlh
https://www.ebay.com/itm/3525939951...ZFNKFGSzy5VZVOx92U72sAkrt3|tkp:Bk9SR_jjmuDJYQ
https://www.ebay.com/itm/1547889706...j3TA+GmS4segrhAPR5PSXjeFJH|tkp:Bk9SR6zJpODJYQ

and some 24/40 elbows.....i get -20psi vacuum with that pump, not sure how much that would change the boiling point of a water ethanol mixture.....

 

[AndyInOregon]

well try a test batch i think you'd need stuff like this...

https://www.ebay.com/itm/2831144135...bDG7Xd/7LIouY8HRDIBSMxG7CfiM|tkp:BFBMiOyS4Mlh
https://www.ebay.com/itm/3525939951...ZFNKFGSzy5VZVOx92U72sAkrt3|tkp:Bk9SR_jjmuDJYQ
https://www.ebay.com/itm/1547889706...j3TA+GmS4segrhAPR5PSXjeFJH|tkp:Bk9SR6zJpODJYQ

and some 24/40 elbows.....i get -20psi vacuum with that pump, not sure how much that would change the boiling point of a water ethanol mixture.....

Thanks for the recommendations! I'm not sure I'm ready to buy equipment yet. If I do, I'll try it on some store-bought wine. I haven't even gotten back to homebrewing yet.

A side note, this would also be a way to reduce the alcohol in drinks, if one is into that kind of thing.

 

[bracconiere]

reduce the alcohol in drinks, if one is into that kind of thing.

no, and that stuff was just some for a science experiment sorta trial run....you'd get a way better still without vacuum here...

this is kinda what i have...i can get a gallon of 65% not a shot....

https://brewhaus.com/moonshine-stills/reflux-still/

8 gallon, you can use it as a pot still or reflux, and i use a 1500watt hot plate with it, and a 1500watt fan sppeed controller, also with a kill-a-watt meter to see the 'heat level' even better then an open flame! it's digital! i see it in watts....those stupis top cooling things just make garbage if you actually use them for anything the ending cool down.....you want to control the head temp from the bottom not at the top, not sure why, but it's been my experience....

 

[doug293cz]

well try a test batch i think you'd need stuff like this...

https://www.ebay.com/itm/2831144135...bDG7Xd/7LIouY8HRDIBSMxG7CfiM|tkp:BFBMiOyS4Mlh
https://www.ebay.com/itm/3525939951...ZFNKFGSzy5VZVOx92U72sAkrt3|tkp:Bk9SR_jjmuDJYQ
https://www.ebay.com/itm/1547889706...j3TA+GmS4segrhAPR5PSXjeFJH|tkp:Bk9SR6zJpODJYQ

and some 24/40 elbows.....i get -20psi vacuum with that pump, not sure how much that would change the boiling point of a water ethanol mixture.....

There is no such thing as -20psi vacuum. You cannot go below -14.695psi, as that is 0 absolute pressure. You are probably getting -20 inches of Hg. Absolute vacuum is -29.92 inches of Hg.

Brew on

 

[bracconiere]

inches of Hg.

well it's a dial gauge so a spring.....it does only go to 30psi, but my wrist gets sore after 20psi... and usually that's enough for a buchner funnel to work....

 

[AndyInOregon]

Was hard to find, but I found this thread I read a while back. The op is in Iceland. Some technical info here.

https://homedistiller.org/forum/viewtopic.php?t=10956
By the way, I studied some college physics and I was an HVAC service tech for a while. Working with refrigeration systems we have to understand phases relative to temperature and pressure. That's what gave me this "new" but not so new idea.

 

[doug293cz]

well it's a dial gauge so a spring.....it does only go to 30psi, but my wrist gets sore after 20psi... and usually that's enough for a buchner funnel to work....

Annotated screen cap from the linked listing for the vacuum pump you have.

Brew on

 

[bracconiere]

Annotated screen cap from the linked listing for the vacuum pump you have.

View attachment 812634

Brew on

i think there is a conversion going on between spring tension....

 

[clearwaterbrewer]

@clearwaterbrewer

I use a pair of Buchi R215 Rotary Evaporators for flavors... For commercial, it exists, it works, it is espensive, and is used more to protect the flavor of what is left after you remove the alcohol... that is N.A. Beer... I present to you the Alfa Laval De-alcoholizer De-alcoholization module

 

[clearwaterbrewer]

Here is my rotovap setup doing cucumber extraction...

 

[passedpawn]

That's a whopper condenser