NA homebrew techniques? (I know, I know)

[Mylo]

Some of the bitterness involved in boiling beer when using it to cook is that you are reducing the volume, and concentrating the bitterness.

Boiling again would have the following affects as far as I can see.

Drive off CO2
Alcohol evaporation
volume reduction
caramelization of beer

You've forgotten loss of all hop aroma and flavor...

I didn't forget... (see above)...




Mylo

[spiderwrangler]

You didn't... CRBrewHound left it out of his list of things affected.

[Field]

Sounds like a question for the next time the Whites are on the Session

I wonder if using a huge pitch, loads of 02, and crashing before the yeast switch from respiration to fermentation could be used to limit the amount of alcohol


I don't know what it would taste like, probably very "green"

[CRBrewHound]

Boiling homebrew is the quickest way to making it taste like shit. IIRC, NA beer is made under a vacuum. Maybe if you hooked up a vacuum pump to a pressure cooker, you could remove the alcohol at a much lower temp, and preserve some of the hop flavor and aroma. Mylo

No offense, but I am not sure I buy that since making beer involves boiling, Can you provide something more as to why you say that. Boiling again would have the following affects as far as I can see. Drive off CO2 Alcohol evaporation volume reduction caramelization of beer So I can see it producing a change in the flavor of the beer, which could be good, could be bad. You would have to re-carbonate (My opinion would be to distill prior to carbonation). Loss of volume would be small as a still does create a vacuum, so only the alcohol would leave the beer, not the water. So the only real issue I would see with this would be caramelization of the beer, which if accounted for in planning, could be mitigated. Now I must say that I have never tried it, so this is all just me speculating about it, which does mean I may be missing stuff.

The flavor gets wicked bitter. Go ahead and boil and cool a little bit of beer and try it out.
I have cooked with enough of it to know that it turns very bitter in a very short time.

Actually, I was talking about using a still to do this, then you control the evaporation rate of the beer, so you would probably get a boost in the bitterness, but not that substantial because you are only making a small change to the volume of the beer, only enough to take out alcohol and the time would probably not be that long, I would think 1/2 hour in a reflux still and you would be down below 1%.

[CRBrewHound]

You didn't... CRBrewHound left it out of his list of things affected.

good point, you would loss some hop aroma and probably some flavor, however, I don't think you would loss that much as a still is a system with a controlled exit. other then the points you allow for the alcohol to leave the system, it is sealed. So the only exit point is a small crack enough to get drops of liquid through.

[CRBrewHound]

Now you guys have peeked my interest enough to give this a try, It will take me a bit to get it done as I am currently building a new rig and have stolen the valves off my old kettles.

I'll report when I have gotten this done and how it worked. Plus this would be a nice addition to be able to offer NA beer at festivals and what not for DD's.

[spiderwrangler]

You didn't... CRBrewHound left it out of his list of things affected.

good point, you would loss some hop aroma and probably some flavor, however, I don't think you would loss that much as a still is a system with a controlled exit. other then the points you allow for the alcohol to leave the system, it is sealed. So the only exit point is a small crack enough to get drops of liquid through.

Well, you did say boiling, rather than just heating. If you are using a still, with good temp control, you would be able to bring it to the temp of vaporization for alcohol and drive it off without bringing everything to a full boil.

It would depend on what temperature the aroma and flavor compounds are driven off at. If they volatize below alcohol, they are gonna get driven off. If they volatize higher than alcohol, then they would largely be retained.

[spiderwrangler]

crashing before the yeast switch from respiration to fermentation could be used to limit the amount of alcohol

Yeast don't really switch from respiration to fermentation in the fermentor. There isn't really an aerobic phase, they will take up oxygen from the wort, but it doesn't get utilized as an electron acceptor, it's used to build other molecules (sterols) in the membrane.