Experimenting with NA beer- should I worry about fumes?

[josephort]

I've got a stout that's about ready to bottle, and I want to try to remove the alcohol from a portion of it. The plan is to try to heat it up to 175-180 F for ~30 minutes as outlined here. Yes, I know I may degrade the flavor and will definitely degrade my own experience, but I'm still going to give it a shot.

My one concern is the fumes. I don't have the equipment to boil outside, so this will happen in my kitchen, either on the stovetop or the oven. If I take 1/3rd of the 6-gal batch and successfully reduce the alcohol from 5.5% to 0.5%, that's ~21 beers worth of gaseous alcohol coming off the kettle. How much of this am I going to wind up inhaling as I stand by checking the temperature, stirring, etc? Is opening a window and trying not to breathe near the kettle enough of a precaution? Should I be worried about combustion, especially in the oven?

The fact that I haven't seen any warnings on any of the articles I've read about makes me think I probably don't need to worry. On the other hand, I feel like very few homebrewers are trying to make NA beer, so maybe there are risks that just don't get discussed much. Any experience or insight would be appreciated.

 

[Vale71]

Don't worry about combustion, the concentration will be well below the ignition point of alcohol.

As for inhaling the fumes, unless you're setting things up in a way that the fumes will all have to go through your lungs before exiting the room you will be inhaling at most a tiny fraction of them und AFAIK unlike other, herm... "recreational substances" alcohol absorption through the lungs is very poor.

 

[Pappers_]

Of the two options, I would think the fumes would be much less concentrated on the stovetop than in an oven.

 

[bracconiere]

i wouldn't go the oven route, i've blown the door open a few times, re toasting wood chips for making wood flavored alcohol....

i'm not sure about blowing your entire house 'open', but it does it in the oven, you probably won't get a flambe with 5.5%, but i would recommend opening a window. because i don't know how pure the alcohol being evaporated would be if the liquid isn't boiling, be careful....

(i wouldn't be too worried about breathing it, i'd figure at least the alcohol's not being totally wasted! )

 

[bracconiere]

Don't worry about combustion, the concentration will be well below the ignition point of alcohol.

even when the water isn't boiling off along with the ethanol?

 

[Vale71]

While the temperature will be somewhat higher than the flash point of a 5% ABV ethanol solution I'm sure the OP will not try and apply an ignition source directly to the liquid's surface just for fun. Even if he did, getting such a low ABV beverage to actually ignite would be no small feat indeed. Just getting warm wine to ignite without first spiking it with some spirit is not that easy. Once the ethanol vapors disperse the concentration will be very low. Just cracking open a window will then provide adequate ventilation.

Keep in mind that he's not distilling so he won't have a heat source in close proximity to a highly flammable ethanol concentrate.

I think the biggest issue (after the lack of alcohol of course..) will be with massive cold-side oxidation. Unless the OP manages to work in an O2 free vessel there will be lots of oxygen ingress and at those temperatures oxidation will proceed very, very quickly.

 

[bracconiere]

because i care about people's safty, i sacrificed one of my 8% ciders, brought it up to 180f, put a lighter to it....you're right, no flame

as food for thought, for someone smarter then me...


i'm not sure how many grams of oxygen are in air, but he's going to be evaporating ~300grams of ethanol.....so 3.3% is the lower limit....

 

[bracconiere]

just thinking, a hot plate to do this outside is only like 15-20 at the hardware store.....

 

[Vale71]

because i care about people's safty, i sacrificed one of my 8% ciders, brought it up to 180f, put a lighter to it....you're right, no flame

as food for thought, for someone smarter then me...


i'm not sure how many grams of oxygen are in air, but he's going to be evaporating ~300grams of ethanol.....so 3.3% is the lower limit....

The limits you quoted are for air/gas mixtures so you only need the density of air to calculate how much alcohol (in weight) you need per cubic meter of air to reach 3.3%. The density of air is 1225 g/m^3 so 3.3% is 40 g/m^3 of ethanol. With 300g he could in theory reach the lower limit in 7.5m^3 of air. A 10m^2 room with a 3m high ceiling already has a volume of 30m^3 and by american standards that is only slighly larger than the average walk-in closet... The lower limit or slighly more is probably what he'll have in the immediate vicinity of the liquid surface as air convection will carry the vapors away very quickly. At the lower limit you'll need a very hot ignition source to actually have ignition as your little experiment has shown.

 

[josephort]

Appreciate all the thoughts so far! My concern with flammability was mostly with the oven- evaporating ethanol into a small enclosed space with a heating element seems much riskier than just letting it disperse into the apartment. I also did a test with just water and found that my oven temperature isn't at all consistent with what I set the dial to, so stovetop seems better across the board.

You definitely can get drunk from inhaling alcohol and it's apparently quite unpleasant. I doubt I'll get much unless I stand over the pot huffing, but it would be terribly ironic if I gave myself an awful hangover in the pursuit of producing NA beer. Whether or not this is likely is probably something that can only be answered with experience, so I'll report back once I've given it a shot!

 

[josephort]

An update for anyone else who wants to try this:

I decided to do just one gallon in part because of my concerns and in part because I didn't want to waste too much beer if it failed. I opted for the stovetop instead of the oven, both because that seemed like less of a fire hazard and because I tested my oven with a pot full of water and found it did a poor job at holding a consistent temperature. I didn't open a window because it was cold, but I did try not to breathe over the kettle, which wound up being tricky because I really had to babysit it.

I didn't start any fires and I didn't feel like I inhaled a significant amount of alcohol. I of course cannot rule out the possibility that a larger batch, a stronger beer, doing it in the oven, or being less careful about breathing wouldn't have caused problems.

What I did find was that holding the temperature constant was really hard. I was shooting for 175F, but would swing up and down around that number, varying by about 15 degrees at the worst. I kept at it for about 45 minutes after which point I supposed most of the booze was gone, although the liquid never stopped gently fizzing. I added priming sugar while it was still going, then chilled, added a bit of the slurry from the original brew, and bottled as normal.

Just last night I taste-tested this NA stout against the regular version it was made from. I would say the regular beer was decent, while the NA version was mediocre. Both beers have a lot of roasty notes; in the normal version these are well balanced against a smooth, full-bodied character, while in the NA version they come across as harsh and acrid. The NA beer is also overcarbonated (I had to add extra priming sugar to account for boiling off CO2 along with alcohol, and I guess I overcompensated), which probably contributes to this issue.

I drank quite a bit over the holidays and especially NYE, so I'll be glad to have these NA beers for a bit of recovery this week. I'll probably try this experiment again, but the difficulty of the process and the disappointing nature of the final product make me a lot less excited about doing this than I was before.

 

[Nate R]

An update for anyone else who wants to try this:

I decided to do just one gallon in part because of my concerns and in part because I didn't want to waste too much beer if it failed. I opted for the stovetop instead of the oven, both because that seemed like less of a fire hazard and because I tested my oven with a pot full of water and found it did a poor job at holding a consistent temperature. I didn't open a window because it was cold, but I did try not to breathe over the kettle, which wound up being tricky because I really had to babysit it.

I didn't start any fires and I didn't feel like I inhaled a significant amount of alcohol. I of course cannot rule out the possibility that a larger batch, a stronger beer, doing it in the oven, or being less careful about breathing wouldn't have caused problems.

What I did find was that holding the temperature constant was really hard. I was shooting for 175F, but would swing up and down around that number, varying by about 15 degrees at the worst. I kept at it for about 45 minutes after which point I supposed most of the booze was gone, although the liquid never stopped gently fizzing. I added priming sugar while it was still going, then chilled, added a bit of the slurry from the original brew, and bottled as normal.

Just last night I taste-tested this NA stout against the regular version it was made from. I would say the regular beer was decent, while the NA version was mediocre. Both beers have a lot of roasty notes; in the normal version these are well balanced against a smooth, full-bodied character, while in the NA version they come across as harsh and acrid. The NA beer is also overcarbonated (I had to add extra priming sugar to account for boiling off CO2 along with alcohol, and I guess I overcompensated), which probably contributes to this issue.

I drank quite a bit over the holidays and especially NYE, so I'll be glad to have these NA beers for a bit of recovery this week. I'll probably try this experiment again, but the difficulty of the process and the disappointing nature of the final product make me a lot less excited about doing this than I was before.

Food for thought- have you considered a sous vide? A great one is $200, but inkbird and annova have smaller good ones for like maybe $80. You could create a tight seal with a small escape hole- let alcohol out and keep oxygen out?
I wonder as mentioned above if the oxygen exposure may affect the beer the most.

Not sure if a sous vide can get to 175 and how much you want to spend- i.e. was this a one-time deal?

 

[CascadesBrewer]

An update for anyone else who wants to try this...

I would be curious to see the results of a test of the ABV. My understanding is that with the "boiling off the alcohol" approach it is hard to reduce the alcohol more than about 50% without more sophisticated equipment. Still maybe worth doing to reduce the ABV of a beer if the flavor is still decent.

 

[day_trippr]

Where's the fun?
I would definitely have put a lit match to the nearly-lidded pot as few times during the cookin' just to see if it'd 'splode

Cheers!