Sous Vide Distillation

[Budapest8485]

I've read a lot about the basics of distilling: Safe materials, pot/reflux still, cleaning a new still, making cuts... More to learn, but I have a good start thanks to the experienced members of this site.

I realize a keg with a condenser column is probably my future, but I wondered if an experienced distiller has any thoughts about a different concept that will make use of stuff I already have on hand. My thought is to put a glass 6 gallon carboy full of homemade wine into an insulated cooler and fill the cooler with water to the same level as the wine. Then put my soux vide in the water and heat it all to the necessary temperatures to distill. I tested the unit and it will easily take the full cooler to at least 190 degrees...probably higher, I didn't test it beyond that level.

So I would have a copper column that's sealed into the carboy opening with a combination of PTFE tape and/or flour paste. The copper pipe sits in there nicely about 1.5 inch in and then makes contact preventing it from dropping in further. There's about an 1/8th inch gap between the neck and the copper pipe that I'd make up for with PTFE tape and/or flour paste. From there, everything is copper over to a copper worm inside a 5 gallon bucket to be filled with ice.

While inferior to the keg designs on this site, I wondered if anything looks like trouble. I have precision control over temperatures...I can raise and lower it one degree at a time and leave it for a long time at whatever temp I select. The temperature inside the carboy will adjust and reach an equilibrium with the surrounding water.

Glass isn't a material listed as safe...I assume it's safe. I don't think thermal shock is a problem at these low temps and slow adjustments. See the rough diagram attached.

[Swedish Pride]

reason glass isn't listed as safe is that it's not.
or at least not guaranteed safe, it's prone to shatter and some older glass even has led in it.
if you happen to get a stoppage in the copper pipe you have in your design you have a nice pressurised glass vessel that's known to shatter by a gnats fart.

you'll more than likely be fine with it, but I'd not recommend it

[NZChris]

A 10% abv wash won't start distilling until 195 F so, unless you live at a very high elevation, it is doubtful you will get any distillation happening at 190 F.

[Budapest8485]

I didn't realize ethanol distilled at higher temps based on abv. I thought it leaves the wine at 173 with adjustment for sea level. The sous vide does allow me to hold a fixed temp as long as I want to...days if necessary.

My normal wine is around 12 percent. I can up it some with sugar additions, but I doubt much above 14 is worth attempting for an amateur wine maker with champagne yeast.

You've given me a new topic to research and understand. Thank you! BTW, I have no doubt the sous vide will go to 195 without a problem. I do however wonder when the plastic of my cooler might be affected...

[Saltbush Bill]

I didn't realize ethanol distilled at higher temps based on abv.

Here is your first problem and something you most likely have not thought about.
You are not distilling just Ethanol, you are distilling a mix of components and you are trying to separate the ethanol "mostly anyway" from that mix.
Here is a list of the mix of components that make up your wash and their boiling temps , what is the boiling point of that mix ?
As soon as you change the ratios of the different things in that wash the boiling point changes.
The ratio of different components of the wash is constantly changing as the lower boiling point ones boil off and leave the boiler/ wash.
Welcome to the science class that is distilling.
• Acetone 56.5C (134F)
• Methanol (wood alcohol) 64C (147F)
• Ethyl acetate 77.1C (171F)
• Ethanol 78C (172F)
• 2-Propanol (rubbing alcohol) 82C (180F)
• 1-Propanol 97C (207F)
• Water 100C (212F)
• Butanol 116C (241F)
• Amyl alcohol 137.8C (280F)
• Furfural 161C (322F)

[NZChris]

I didn't realize ethanol distilled at higher temps based on abv. I thought it leaves the wine at 173 with adjustment for sea level. The sous vide does allow me to hold a fixed temp as long as I want to...days if necessary.

My normal wine is around 12 percent. I can up it some with sugar additions, but I doubt much above 14 is worth attempting for an amateur wine maker with champagne yeast.

You've given me a new topic to research and understand. Thank you! BTW, I have no doubt the sous vide will go to 195 without a problem. I do however wonder when the plastic of my cooler might be affected...

I'm stripping a rum wash today, stripping until the wash temperature is around 111.5 F. Sometimes I go higher. At those temperatures, there would be so little heat transfer through glass that distillation would cease long before I reached my target.

[rubelstrudel]

This is an interesting project. It is a "plastic fantastic" still made with better materials, and thus hopefully none of the major drawbacks of these plastic stills.
You'd need to keep the water basin covered to avoid heat loss through evaporation but that is easily done.
This will be a very very slow still. Your main problem will be to create enough pressure inside the "boiler" to push the gas out through your condenser pipe.
But there is really no serious risks in this setup. You can place it outdoors in cold/temperate climate for days and there is low direct risk of fire or explosions.

Low temp condensation distilliation like this does not rely on reaching the vapour temperature of the compounds in the mash we want to separate out (alcohol) but instead on direct evaporation at lower temperatures. Just like water evaporates at all temperatures, not just boiling.

Your main problem will be that the vapour heavy gas mix in your "boiler" will be to heavy to rise out through the copper pipe and the evaporation from the mash surface will stop at some point without being able to push the gas through the pipe, since the pressure from the outside air is to high. The second problem will be that you have no convection/movement in your mash, and since evaporation only happens on the surface, you will probably get little alcohol fumes in the air.

You could remedy the pressure issue by leading a small trickle of fresh air into the boiler, maybe with an aquarium pump and another thin copper pipe. This will increase the gass pressure and push the vapour mix out through the only exit - your condenser. If you put the air pipe outlet at the bottom of your boiler jar, the bubbles will probably make enough convection movement in the mash to allow alcohol to evaporate more easily.

This setup will most likely only function when the ambient temperature is really low. Or your gathered product will just evaporate from your collection jar, at the same speed you collect it.
But during winter, putting this contraption outdoors in freezing weather should work nicely.

On another note. Temperature control will not really matter here. You could just the same just drop the sous vide heater, and use an aquarium heater directly into the mash, or a piece of heating cable wrapped around the boiler and then insulated with fiberglass. The point is just to add heat. The evaporation will use that heat as liquid goes over to gas. You need to add heat continously, and at some point there will be an equilibrium between heat added and heat extracted. Then again - the sous vide insulated tank will add another layer of security against glass breaks. If your glass boiler breaks inside the sous vide container - nothing happens. Mash will just mix with water and keep nice and warm until you turn off the heat.

Try it out, take pictures and show us what happens. You will not create world class spirits, but if your mash is good, you will get a decent drop of neutral.
I have done experiments with low temp condensation stills, and the results I ended up with weren't bad at all - with proper care.

[Kareltje]

That was a good comment, Rubelstrudel!

I might add:
I guess there will be a bit draft of vapour from the warm boiler unto the ice cooled condenser.
Very good insulation will be needed.
The glass of the carboy is no problem if it is filled with 12 % wash. If it breaks, which is unlikely, the 12 % wash will be diluted to a 6 % wash and I never have heard of beer setting fire.

I would prefer not to use a heater, but to set up the vessel of water in a sun oven. Properly build with a set of mirrors this can reach cooking temperatures for free! Agreed: you have no control over heat input and thus not over distilling speed, but you will need a spirit run anyway.

Yes, I too would like to see pictures and a report on progress!

[Mikey-moo]

I'll save you some time. I've tried using sous vide equipment for distilling - they don't work very well:

1) they only just get hot enough (I had to set mine for 99.9ºC to get any output at all)
2) they cycle on and off which smears your product

But if you're anything like me, you'll try it anyway. Let us know how you get on.

[Pikey]

Odd really - I've been thinking about using my electric pot for sous - vide - never even considered othr way around !

[still_stirrin]

Well, let’s think “outside the box” for a moment.

What if you could lower the boiling point of the mixture? Suppose the boiler, worm, and collection vessel were all closed (a sealed system) and you pulled a vacuum on the system...you could actually boil at the sous vide temperatures. But then again, vacuum distillation has its own set of dangers and limitations as well.

Search for and discover the options of “vacuum distillation”. It has been done before.
ss

[rubelstrudel]

The neat thing about low temperature condensation stills however is that you are not boiling, but relying on evaporation below the boiling point. You just leave the thing there for days dripping slowly. And it does really work - at least as long as the ambient temperature is low enough. My old plastic fantastic experiment produced about 50cc of 40%ABV per day when the ambient temp was below freezing. Less when it was warmer. It would be really cool to know if the idea to push air through the still to incrase the pressure enough that the vapour is pushed out would work. Maybe I'll make my own experiment this winter.

[Budapest8485]

This is an interesting project. It is a "plastic fantastic" still made with better materials, and thus hopefully none of the major drawbacks of these plastic stills.
You'd need to keep the water basin covered to avoid heat loss through evaporation but that is easily done.
This will be a very very slow still. Your main problem will be to create enough pressure inside the "boiler" to push the gas out through your condenser pipe.
But there is really no serious risks in this setup. You can place it outdoors in cold/temperate climate for days and there is low direct risk of fire or explosions.

Low temp condensation distilliation like this does not rely on reaching the vapour temperature of the compounds in the mash we want to separate out (alcohol) but instead on direct evaporation at lower temperatures. Just like water evaporates at all temperatures, not just boiling.

Your main problem will be that the vapour heavy gas mix in your "boiler" will be to heavy to rise out through the copper pipe and the evaporation from the mash surface will stop at some point without being able to push the gas through the pipe, since the pressure from the outside air is to high. The second problem will be that you have no convection/movement in your mash, and since evaporation only happens on the surface, you will probably get little alcohol fumes in the air.

You could remedy the pressure issue by leading a small trickle of fresh air into the boiler, maybe with an aquarium pump and another thin copper pipe. This will increase the gass pressure and push the vapour mix out through the only exit - your condenser. If you put the air pipe outlet at the bottom of your boiler jar, the bubbles will probably make enough convection movement in the mash to allow alcohol to evaporate more easily.

This setup will most likely only function when the ambient temperature is really low. Or your gathered product will just evaporate from your collection jar, at the same speed you collect it.
But during winter, putting this contraption outdoors in freezing weather should work nicely.

On another note. Temperature control will not really matter here. You could just the same just drop the sous vide heater, and use an aquarium heater directly into the mash, or a piece of heating cable wrapped around the boiler and then insulated with fiberglass. The point is just to add heat. The evaporation will use that heat as liquid goes over to gas. You need to add heat continously, and at some point there will be an equilibrium between heat added and heat extracted. Then again - the sous vide insulated tank will add another layer of security against glass breaks. If your glass boiler breaks inside the sous vide container - nothing happens. Mash will just mix with water and keep nice and warm until you turn off the heat.

Try it out, take pictures and show us what happens. You will not create world class spirits, but if your mash is good, you will get a decent drop of neutral.
I have done experiments with low temp condensation stills, and the results I ended up with weren't bad at all - with proper care.

Very good points. Movement of the wine in the boiler is something I had not considered. Maybe if part of the wine is above the warm water level it would create the convection movement inside the carboy...then heat is being lost... What a conundrum!

This is a new heavy-duty carboy. I need to do a test and see what happens...I have everything ready, so I can just do it and see what happens.

Thanks for all the input...I'm happy with the feedback!

[Budapest8485]

reason glass isn't listed as safe is that it's not.
or at least not guaranteed safe, it's prone to shatter and some older glass even has led in it.
if you happen to get a stoppage in the copper pipe you have in your design you have a nice pressurised glass vessel that's known to shatter by a gnats fart.

you'll more than likely be fine with it, but I'd not recommend it

Your concerns are noted. I am going with a stainless steel stock pot instead...same concept. Thanks.

[The Baker]

The neat thing about low temperature condensation stills however is that you are not boiling, but relying on evaporation below the boiling point. You just leave the thing there for days dripping slowly. And it does really work - at least as long as the ambient temperature is low enough. My old plastic fantastic experiment produced about 50cc of 40%ABV per day when the ambient temp was below freezing. Less when it was warmer. It would be really cool to know if the idea to push air through the still to increase the pressure enough that the vapour is pushed out would work. Maybe I'll make my own experiment this winter.

Interesting. One day I will look at using two my big pyrex bowls (maybe twenty litres each?) as a solar still and a lot of the info about low temperature distillation is relevant.

Geoff

[HDNB]

I'll save you some time. I've tried using sous vide equipment for distilling - they don't work very well:

1) they only just get hot enough (I had to set mine for 99.9ºC to get any output at all)
2) they cycle on and off which smears your product

But if you're anything like me, you'll try it anyway. Let us know how you get on.

yeah it would be awesome for someone to report back with some data. we all heard about people trying it before, but they always seem to disappear before results come in.

Good luck!

[rubelstrudel]

Using a sous vide heater directly in the wash does have the effect of smearing the distillation with the power cycling on and off, but when you use a sous vide basin filled with water as a heat magasine, this problem would more or less go away. The heat transfer from the heat basin into the "boiler" would be as constant as it is possible to get. It would be possible to get a boiler bubbling off ethanol with this water basin, but I think it is easier to build a system that does not boil, but just evaporates at lower temperatures. This is the principle behind the classic "plastic fantastic stills" - and they do indeed work, only to make one with safe materials is just as expensive as building a real still - so there is not much call for something that will only ever produce 50cc /day, and then only during arctic winter temperatures.

Here is a schematic of a low temp still I actually built and had running a winter month.

Condensation Still

I kept the wash temp at 45C while the outside temp was -5C. The still worked like a charm. I could even distinctly notice the change in distillate composition as I emptied the accumulated product each night (making cuts). Of course it is not a real fractioning still - but it does work, and if built with proper materials and with care given to the wash, would produce a decent enough drop.

When using Sous Vide heater, I imagine something more like this:

Sous Vide Still

The main addition is to add some air, for convection, and to push the saturated air out, to let vapours condense.
My main interest here would be what happens when you keep your wash at just exactly below the boiling temperature of Ethanol - 77-78C. How will that make your distillate? How slow will it be? Will you get nice cuts?

[Budapest8485]

Success...no pictures coz I'm paranoid about such things. The early stuff that came out was a little cloudy looking. I practiced making cuts, with the first two ounce and kept it in a different jar. Then I collected about 1.5 pints of clear stuff. It took about 4 hours and it was still coming out. I figured I was getting mostly water at the end when I dipped my finger in and it didn't have the same bite. I didn't notice that tails tasting any different than the Hearts...again, I just took maybe 5-6 tastes dipping my finger in.

Around 180 I saw the first drops come out...I don't have thermometer installed, so I don't know how hot it was inside the boiler. I went as high as 200 on the sous vide. I had no trouble with this temp and the dial will adjust to 210. I don't have a proof and tralles hydrometer...I now see that I'll need one to understand what I've actually accomplished. I burned it and saw blue flames at first...then it turned to mostly blue with yellow peaks. Does that mean anything to you?

I used 6 bottles of pinot noir...stuff I made in 2013 that I'm not happy with. I consider this a still cleaning run as I don't intend to use it for anything other than cleaning...I'll put it back through the system as a final clean out before making anything fit for consumption.

I'm upgrading to a jacketed water fed condenser soon. The bucket with the worm is okay, but I want a more compact less maintenance system.

I have a lot of old wine around. Since I did this in a stock pot instead of the glass carboy, I'm going to try it on my kitchen range next time. The vent hood over it will prevent a tall reflux column, so I'm already researching how to use a thumper... This all is happening much easier than I thought it would.

[rubelstrudel]

We really want to see what you have made. It would be great with some pics.

[Budapest8485]

Bought a proof hydrometer. First pint is 126 proof. The second half pint is 102 proof.

I need to read a bit more to figure out if these are expected results for a pot still.

[rubelstrudel]

That is pretty much what you'd expect.