Boiling beer

Just out of curiosity, how destructive to the flavor would it be to boil the beer precarbonation, then bring it back down to temperature?

It'll taste horrible, in my experience.

I would think at the very least it would be oxidized all to heck and back. That is just a wild guess though.

Why the hell would you want to do that???

Isn't this similar to how non-alcoholic beers are created? Well not boiled, but heated up to burn off the alcohol after fermentation?

Alcohol has a lower boiling point then water....I personally don't see the reason for making it, so I haven't tried making my beer near beer. But I have heard that the best way to do it is heat it in an oven for 30 minutes (leaving the oven at 175-180 will "boil" off the alcohol and not the water). Although "non-alcoholic beer" is not really non-alcoholic: because there's a little bit of condensation, that beer still has around .5% alcohol.

It would completely destroy the yeast so you'd have to force carb or add new yeast, you'd boil off all the alcohol, and waste all the time, money and purpose of brewing it in the first place.

If you're doing this to make near beer do a Google search for azeotrope. The 95/5 H2O/EtOH azeotrope is what you're after. Based on a combination of my hombrewing knowledge and lab experience I would go about it by purging the kettle with CO2, then racking the beer into it (the denser CO2 will provide a bit of a blanket over the beer). Put it on the stove or burner and heat it. Have a termometer in there. The liquid should boil somewhere right above 78 C for a while. The temperature should stabilize here until the majority of the EtOH is driven off (with some water), then begin to climb. As soon as the temperature begins to go up cut the power and rack it into a keg purged with CO2 and keep it hooked up to the gas under pressure to keep it from creating negative pressure. The CO2 in solution will outgas as you're heating it, which should protect against oxidation, and as the mixture is heating the solubility of gasses is constantly lowered in the liquid phase so I wouldn't think you'd have an oxidation problem there. Once you hit boiling the H2O/EtOH gas phase that's being created should serve to protect the liquid from atmospheric gasses, not to mention that the solubility of those gasses will be extremely low and the solution will already be saturated. I think that the only real place where you could pick up oxygen would be in the cooling phase, which is why I'd do it under CO2 pressure.

After all that, I have no idea how raising the temperature to 80ish C would effect the other components of the beer. It might make it undrinkable, or they may all be fine.

trigger said:

If you're doing this to make near beer do a Google search for azeotrope. The 95/5 H2O/EtOH azeotrope is what you're after. Based on a combination of my hombrewing knowledge and lab experience I would go about it by purging the kettle with CO2, then racking the beer into it (the denser CO2 will provide a bit of a blanket over the beer). Put it on the stove or burner and heat it. Have a termometer in there. The liquid should boil somewhere right above 78 C for a while.

Click to expand...

Close but no cigar (unless of course he can ferment his beer up to 95% abv). a 5 percent ABV beer would boil at 95 degrees C. By the time it got up to 98 degrees or so you would be looking at around 1 percent alcohol. There is a real point of diminishing returns above that (ie more water and less alcohol is removed so that it actually is very difficult or impossible to get to 0 alcohol while any water remains).

The problems with this are that thermometers with the resolution and accuracy required for this would be very expensive. On top of this, compensation would have to be made for altitude and atmospheric pressure as they would both have a significant impact on boiling point. And last but not least, the solution is not just alcohol and water, but dissolved sugars as well which would have a small but measured effect on boiling point.

Now to remove some alcohol from beer, it would not be necessary to boil it, of course knowing how much was removed is the trick, and it is never all gone until the water is all gone.

I like brewing beer, but if I need near beer, I go to the store. This has the added benefit when the local constabulary pays me a visit while i'm out fishing they can see its O'Douls. Of course the conversation would be interesting when they ask me what I'm drinking and I say 'beer, but I boiled it to 99 degrees, I swear!'

As always YMMV