Minimizing Oxygen When Evaporating Alcohol for Low/No Alcohol Beer

[alooper86]

I have begun split batching some of my beer as my wife has stopped drinking alcohol. I will split the batch into two separate 6 gal ss brew buckets and ferment completely. One I will keg as I normally would but the other I try to do low/no alcohol for her. My first attempt with a wheat beer was a success but I cannot figure out how to minimize O2 as there is a ton of it in my process now.
I will rack from fermenter into boil kettle and bring to 175F and hold for 30-45 min to evaporate alcohol. Then I will chill using plate chiller and pump into keg. Obviously this method is exposing the beer to O2 for over an hour which is less than ideal. Any suggestions on how to minimize O2 for this process?

 

[Brooothru]

I have begun split batching some of my beer as my wife has stopped drinking alcohol. I will split the batch into two separate 6 gal ss brew buckets and ferment completely. One I will keg as I normally would but the other I try to do low/no alcohol for her. My first attempt with a wheat beer was a success but I cannot figure out how to minimize O2 as there is a ton of it in my process now.
I will rack from fermenter into boil kettle and bring to 175F and hold for 30-45 min to evaporate alcohol. Then I will chill using plate chiller and pump into keg. Obviously this method is exposing the beer to O2 for over an hour which is less than ideal. Any suggestions on how to minimize O2 for this process?

Long shot idea, but if you have a RIMS tube and a short (2 1/2 gal keg), you could submerge a mostly full keg in a boil pot and either vent through an open lid-mounted PRV or a spunding valve set to open at a very low pressure differential. Set the water bath temperature to 175F. I'm not sure how to ensure when the beer in the keg actually reaches an evaporative temperature.

Perhaps the keg lid could be left off with the keg filled to the top of the lip. That way the only surface/oxygen interaction would be limited to the area of the lid opening, the evaporating alcohol would be free to escape, and you could continuously monitor temperature.

Might work.

Brooo Brother

 

[bkboiler]

I don't have a lot of experience with this, but wouldn't a still be ideal for this purpose?
Only other thing I could think of would be a purged vessel, but that's even more expensive than a still

 

[Cool_Hand_Luke]

A still or a vacuum still would likely be the best way to handle this. The advantage of a vacuum still would be once you are done, you could backfill the vessel with CO2 and pressure transfer into a keg once done. Here’s a link to another thread with some info on that: Creating an NA (Or...how I neutered my beer)

You may want to consider sending a sample of your NA beer off for analysis. I did this on a test run of my system that ran for 4 hours, and the resulting beer was still nearly 2% ABV. With your procedure you will evaporate faster with the additional surface area, but there is a decent chance that 30-45 minutes is not sufficient to get down to less than 0.5% ABV.

 

[Vale71]

The problem with heat removal of alcohol is that temperature also greatly accelerates oxidative reactions. This means that acceptable threshold levels for O2 exposure become so low that any exposure will yield unacceptable results.
The only way to do this with acceptable results would be in a sealed, purged vessel with a blow-off. One side effect would be that nearly all CO2 will escape so it would be pointless to carbonate the beer beforehand as it will need to be forced carbonated again at the end of the process.
A vacuum extractor would allow you to conduct the process at a lower temperature minimizing oxidative damage but it would strip the beer of even more aromatic compounds. I'm afraid the resulting NA beer would be quite dull.

 

[Brooothru]

The problem with heat removal of alcohol is that temperature also greatly accelerates oxidative reactions. This means that acceptable threshold levels for O2 exposure become so low that any exposure will yield unacceptable results.
The only way to do this with acceptable results would be in a sealed, purged vessel with a blow-off. One side effect would be that nearly all CO2 will escape so it would be pointless to carbonate the beer beforehand as it will need to be forced carbonated again at the end of the process.
A vacuum extractor would allow you to conduct the process at a lower temperature minimizing oxidative damage but it would strip the beer of even more aromatic compounds. I'm afraid the resulting NA beer would be quite dull.

There's just something about NA beers that is not satisfying, and it's not simply the lack of a "buzz." I've never been able to identify the subtle missing component, but unmistakably something is lacking that otherwise would make the consumption more enjoyable. Maybe it's texture or mouthfeel or an esoteric "lightness" that results in a less pleasurable beverage. I really don't know 'what' but I know it's somehow less than 'whole'.

I get the same reaction to gluten free foods. I love pasta. GF pasta tastes like cardboard. Same with bread or any other baked good made with whole flour substitutes. I know you can't taste gluten. The caloric load between regular and GF foods are similar. Textures are nearly the same. Not sure about carbs, though alcohol is high in carbs so maybe in some obscure way I'm sensing the lack of carbs?

In any event I "feel" like there's some fundamental yet undefined difference in NA beer that makes it less appealing and less enjoyable than regular beer. Whatever "it" is, I wish it could at least be identified and quantified.

Brooo Brother

 

[Vale71]

What you're missing is simply the alcohol. It does have both a taste and a mouthfeel. Any alcoholic drink is simply not the same without it.

 

[Brooothru]

What you're missing is simply the alcohol. It does have both a taste and a mouthfeel. Any alcoholic drink is simply not the same without it.

That's got to be it. I guess my point is that the contribution of alcohol to the overall subjective enjoyment of the beverage is not directly proportional to its volume. One ml of Ever Clear on my tongue is an excruciating experience whereas 1 ml of ethanol in a 5% ABV ale or lager is pleasurable. I'm not cognitively aware of the taste or mouthfeel of ethanol in either case (only the alcohol burn of the Ever Clear), but subtly below that threshold of recognition I'm clearly sensing a difference between the 5% and the NA beers. I just can't describe in words what that difference is, though the 5%er is preferable to the NA.

Brooo Brother

 

[Cool_Hand_Luke]

What you're missing is simply the alcohol. It does have both a taste and a mouthfeel. Any alcoholic drink is simply not the same without it.

This isn’t really helpful to the OP though. I completely agree, but what they are asking is how can I improve my process to make the NA beer as good as it can be. It will never be equivalent to the alcoholic version, but it could still be improved. It sounds like his wife liked the first attempt OK (although I suspect it is not actually NA).

@alooper86, if you are interested I’d be happy to supply more info on how to implement a vacuum process. Vale71 is correct though on any heat based removal process will remove many other organic volatile compounds in addition to the ethanol that provide flavor to beer. This will result in less body and flavor. Although none of this is black and white, all of these compounds have different boiling points, so their respective vapor pressures at 173F will dictate how quickly they are lost through the process. And if you continue to experiment you may find certain beer styles and yeasts work better.

 

[Vale71]

This isn’t really helpful to the OP though.

That's because I was directly responding to another poster who started a tangential discussion.

 

[Cool_Hand_Luke]

That's because I was directly responding to another poster who started a tangential discussion.

Got it. Missed that since it wasn’t quoted. Re-read it and I see that was clearly your intent. My apologies for assuming it wasn’t.

 

[Vale71]

No worries. I try not to quote lenghty posts to avoid cluttering the page. Sometimes it backfires. No big deal.