Ice concentration

[Stoat on a rope]

The freezing point of ethyl alcohol is -114C, so to remove it via crystallisation would be extremely difficult, even when BrewDog produced end of history, they were only taking it down to -90 or so, so it's not going to crystallise and increase the concentration of methanol relative to ethanol, (in geology terms you have cooled your magma below the crystallisation of olivine and pyroxene but not Na rich plagioclase or quartz!)

The problem with regular distillation is the methanol has a lower boiling point so it fractionates out of solution first, followed by the ethanol second, and there is your risk of concentrating methanol, get the temperature wrong and you could be only collecting the bad stuff.

[Dr. Dextrin]

Yes, you're right, I see ethanol does have a lower freezing point than many of the obvious nasties. In that case I'd expect nasty-rich crystals to freeze first and leave the concentrated ethanol liquor relatively deficient in nasties. That's purely guesswork, of course. The presence of sugars might also complicate things.

[mrmojorisin]

Have now had 2 litres of chocolate stout in my freezer for about 3 hours, almost frozen but I'll start the thaw in the morning. Will update as and when.

[Secue]

nice one mr mojorisin, I'm thinking about freezing a sample of my extra strong vintage ale when bottling...hmmm. oh wait though, watched a video on youtube that recommended low hopped beers be frozen, as it also concentrates the bitter profile when concentrating the alcohol.

[jordanchaos]

Lets see some pics!

[mrmojorisin]

Lets see some pics!

As if by magic:



Took the first runnings, if you will, and my god they were strong, just tasted of alcohol. By the time I'd gotten to 3/4 of a pint it was definitely drinkable.....not exactly pleasant but I guess if you wanted to get blind drunk.....

[jordanchaos]

HAHAHA that looks exactly the same as mine. same results too by the look of it!!

[mysterio]

This is called freeze distilling and like other forms of distilation is illegal without a licence

This discussion has been done before - Brewdog claim you do not need a license since it is beer and not spirit. On a technical level very hard to get right as you need exceptionally good beer to start with before freezing (this is the way eisbock is produced). I think mysterio had tried End of History and said it was revolting...

Yes it was undrinkable, I tried it with the CEO watching a group of us (mostly hardcore beer lovers) try it and he was clearly embarrassed by the reactions, so much so that he came over and advised that it tastes better with a block of ice.. !