[horsebox]

Using lets say vodka as an example wouldn't it be possible to separate the alcohol from the water by freezing the water and filtering out the alcohol? I only thought about this now and I assume if it were this simple people would be doing it but I don't understand why this wouldn't work.

[Grundalizer]

You could do it if you had a better freezer.   Conventional freezers don't go low enough to freeze vodka/whiskey that's why people put them in the freezer in the first place.  Ethanol has a freezing point of -174 degrees F.  So I'm guessing you'd have to get somewhere down in the -60's range possibly before the water in the vodka could freeze, although I don't know, as I've never done the experiment.  Finding an industrial freezer is a lot harder than just putting a candle under a pot of vodka and then using a condenser.

But there you go, a science project, at what temperature does vodka freeze, and how much alcohol is recovered. 

[billnotgatez]

I have never tried it but people have said it works
Maybe the energy used is not as favorable as regular distilling

[JGK]

I believe you can, however, remove some of the water by freezing the vodka and then adding ice to it .If you keep this in a freezer the ice attracts the water and freezes it growing the size of the piece of ice added which can then be removed.

[billnotgatez]

I have often wondered if you can get a high concentration of alcohol using freezing and rather than distillation, but never had the time to read up on it or experiment.

[Borek]

Could be urban myth, but they say that's the way they deal with the problem in Siberia.

[csrscience.com]

Dry ice might be able to get it could enough to freeze out some of the water, while leaving the ethanol liquid. I think it may just turn into slush however.

The ice cube trick would be very interesting to see, but it seems to me like the ice cube just might melt away into the alcohol.

Update this thread if you ever try it. It interests me.

[kem]

you can concentrate alcohol from wine by freezing it using the method in this video:
http://www.youtube.com/watch?v=rME3Q8NCWQM

i dont think youll be able to freeze water out of vodka.

[horsebox]

You could do it if you had a better freezer.  

Well my line of thinking was that the water would freeze at 0C but the ethanol would remain a liquid. I've put vodka in the freezer before though and the whole solution remained a liquid so theres obviously something I'm missing here.

you can concentrate alcohol from wine by freezing it using the method in this video:
http://www.youtube.com/watch?v=rME3Q8NCWQM

i dont think youll be able to freeze water out of vodka.

I have some wine to experiment with at the moment so I'm going to test this one out now.

[Sep]

You could do it if you had a better freezer.  

Well my line of thinking was that the water would freeze at 0C but the ethanol would remain a liquid. I've put vodka in the freezer before though and the whole solution remained a liquid so theres obviously something I'm missing here.

you can concentrate alcohol from wine by freezing it using the method in this video:
http://www.youtube.com/watch?v=rME3Q8NCWQM

i dont think youll be able to freeze water out of vodka.

I have some wine to experiment with at the moment so I'm going to test this one out now.

pure water freezes at 0 degrees C. think of it this way. at 0 degrees C the water molecules lose enough energy and vibrate and jump around less, enough less that their molecular attractions attract each other and they crystallize. Remember thats pure water. At 0 degrees C a water and alcohol mix will want to do the same, however, there is some sort of impurity in the water. In this case alcohol. The principal works with any substance or impurity. Anywho, the water wants to crystallize, but there is something in the way, so it cant.

Honestly the problem with freezing system and methods is the energy. With heating you add the heat(energy) and you get your result. With cooling, you have so many factors. It's not as effecient, too many places where youre losing energy.

Though, does anyone know if you could just put vodka in a centrifuge and get it to separate? I assume once you stop the machine it will just mix back up?

A system like the enrichment of uranium-235 would work, and it will give you almost pure alcohol, but its both over kill and inefficient, though interesting. lol. Still its centrifuging, though more advanced.

[vmelkon]

I'm sure it will work at some very low temperature but you might have some water left in the ethanol. You would have to do zone cooling to achieve a high purity.

The best method is osmosis and this is what is used to make ethanol fuel for cars and you can make 99.9% ethanol.

[khemikuhlz]

From what I've read, it seems that you cannot get a very high concentration of ethanol from freeze distillation, by conventional means anyway. Also, the increased concentration of ethanol occurs alongside the increased concentration of some undesirable contaminants.

Freeze distillation is outlawed in some parts of the world because it can concentration certain compounds to such a level where they become toxic to the consumer. But there are some beverages that are created via this method such as ice beer which can often have up to ~40% ethanol. It's been done throughout history.

Freeze distillation runs into the same problem classic distillation does in regards to azeotrope formation, even if the method is "perfected" there will be a ceiling you hit in regards to the percent concentration you can reach via fractional freezing.

Hope this is helpful.

[stewie griffin]

khemikuhlz is right about the beer... check out this latest Time magazine article (http://www.time.com/time/business/article/0,8599,1978705,00.html) about "freeze-distilling" to get high abv beers named Tactical Nuclear Penguin, Sink the Bismarck, and so on.