Driving off Fusel Alcohols

[mwsenoj]

I just read the "How to make an NA beer" article on HBT recently. I also just made a batch of double oatmeal stout that, when cooling it post boil, only got to about 85°F when I pitched since that is what temp my tap water is. Fast forward a month or so, the yeast are now telling me what I already knew, that I should have let the wort cool further before pitching. While the upfront flavor is awesome, the beer is "hot" with what I think are fusel alcohols.

Background story in place, I saw the NA beer article and am now wondering if I might have any success simmering the beer at the boiling point of fusel alcohol to try to get the levels below the taste threshold. So, 1) does anyone know an approximate boiling point for fusels, and 2) anyone ever tried it or have any relevant research that might help me decide how hairbrained my idea is or isn't?

 

[Talgrath]

Given that fusels are alcohol, the boiling point would be about 173F. That said, trying to boil of fusel alcohols runs into a few problems:

1. You're going to oxidize the hell out of the beer, which comes with its own flavor problems.
2. You're going to kill whatever yeast remains in your beer, given that you're bringing it near boil you will likely get some very bad flavors from this as well.
3. You're going to boil off all of the alcohol, not just the fusels.
4. You're going to denature any proteins, esters or fatty acids created by your yeast, which helps give your beer flavor as well.

If you've got a fusel flavor you've got two options, suck it up and drink it, or dump it; that's it, sorry, there's no magic way to fix this one.

 

[Scubadude918]

Hot liquids drive off dissolved gasses such as co2 and oxygen. No fear of oxidation in heating the beer. I can't speak for the other issues.

My .02

 

[boydster]

I think, since fusel alcohols are longer chain alcohol molecules than ethanol, they will have a higher boiling point so you will drive off most of the ethanol before you even begin eliminating fusels. That's why distillers get rid of the first and last bits (methanol and higher alcohols, respectively).

 

[Auger]

Correct - fusels are typically made up of propanol, butanol, a bunch of other crap, all of which has a higher boiling point than ethanol and comes out in the tails of the boil. I guess theoretically you could distill your beer, save everything you take off, toss the tails, and add the ethanol back in...but it would probably be easier to just make a new batch.

 

[mwsenoj]

Maybe I'll just boil it and then add some vodka to it.

Time + matter + chance and idiocy = crappy beer

 

[Auger]

Or, save time, drink the vodka and dump the beer.

 

[Talgrath]

Maybe I'll just boil it and then add some vodka to it.

Time + matter + chance and idiocy = crappy beer

Sometimes, it's better to just dump it and call it a day, even the pros have bad batches sometimes.

 

[BeerGrylls]

Take it as a learning experience, and give the beer to that annoying friend who says "I never get hangovers"

 

[JonM]

Wait - do you mean a double batch of oatmeal stout or a batch of double oatmeal stout? If the latter (and if I'm correct in assuming that "double" means extra strong), then even a well made strong beer is going to be "hot" after only a month. Don't assume it's fusel-y just yet. It might be just fine after it sits for a while.

 

[IJesusChrist]

I like the science behind this question (although I'm unlikely to enjoy the beer).

As stated above, fusels are going to have higher bp than ethanol. However, since their concentration in the beer is going to be much less than ethanol, it is highly likely they would evaporate/distill off quicker than ethanol since they are usually quite volatile. 2m2b is my favorite fusel alcohol, but thats for another discussion.

First - if you want to experiment with this, do it in small batches. Don't do anything to the whole batch all at once. That is stupid science. So, if you choose to proceed, do it in 1 cup volumes.

Test 1:
Simmering. Simmer 1 cup of your beer for 10 minutes, taste, 10 minutes, taste, etc. Fusels are volatile so they may drive off quickly!

Test 2:
Esterification - time dependent. Add some acid blend normally used for wine, at a lower dosage than that specified for wines. Let this sit for a few months. The acids & fusels will esterify over time and may produce an interesting taste.

Test 3
Esterification - heat dependent. Same as above but use simmering/quick heating to drive the reaction. Kind of like test 1+2.

Test 4:
Simply let it age out... over time alcohols and acids will esterify. With a low acid profile though this will take an incredibly long time.

Good luck

 

[mwsenoj]

Wait - do you mean a double batch of oatmeal stout or a batch of double oatmeal stout? If the latter (and if I'm correct in assuming that "double" means extra strong), then even a well made strong beer is going to be "hot" after only a month. Don't assume it's fusel-y just yet. It might be just fine after it sits for a while.

Ya, double strength. I oxygenated with a 0.5 micron stone and pure o2 and pitched 2 packets of dry yeast. The only reason this fermentation was not ultra happy was because of the 85°F pitching rate.

My brewing buddy suggested we call it and open the keg this weekend at a guys night I am hosting. The stuff is good tasting, a ton like Samuel Smiths Oatmeal Stout, but with a boozy characteristic that is not the same as a stuff barleywine.

 

[mwsenoj]

I like the science behind this question (although I'm unlikely to enjoy the beer).

As stated above, fusels are going to have higher bp than ethanol. However, since their concentration in the beer is going to be much less than ethanol, it is highly likely they would evaporate/distill off quicker than ethanol since they are usually quite volatile. 2m2b is my favorite fusel alcohol, but thats for another discussion.

First - if you want to experiment with this, do it in small batches. Don't do anything to the whole batch all at once. That is stupid science. So, if you choose to proceed, do it in 1 cup volumes.

Test 1:
Simmering. Simmer 1 cup of your beer for 10 minutes, taste, 10 minutes, taste, etc. Fusels are volatile so they may drive off quickly!

Test 2:
Esterification - time dependent. Add some acid blend normally used for wine, at a lower dosage than that specified for wines. Let this sit for a few months. The acids & fusels will esterify over time and may produce an interesting taste.

Test 3
Esterification - heat dependent. Same as above but use simmering/quick heating to drive the reaction. Kind of like test 1+2.

Test 4:
Simply let it age out... over time alcohols and acids will esterify. With a low acid profile though this will take an incredibly long time.

Good luck

Thanks for a great response! I will try to to try this out this weekend.

 

[MindenMan]

Quite a while back, I had a batch of alcohol "hot" hard cider that smelled like acetone. Acetaldehydes, are formed with too warm fermentation temperatures. I filled the airlock with vodka, and stuck in the closet for a month or two. I am guessing due to the change in temperature during the time it was in the closet, it was able to breathe the fumes off w/o oxidizing.

 

[JonM]

Ya, double strength. I oxygenated with a 0.5 micron stone and pure o2 and pitched 2 packets of dry yeast. The only reason this fermentation was not ultra happy was because of the 85°F pitching rate.

My brewing buddy suggested we call it and open the keg this weekend at a guys night I am hosting. The stuff is good tasting, a ton like Samuel Smiths Oatmeal Stout, but with a boozy characteristic that is not the same as a stuff barleywine.

Was it 85 degrees the WHOLE time it was fermenting? If you got the temps down to something reasonable within 24-48 hours of pitching, then I bet everything is fine. You might have a perfectly wonderful beer that just needs a little time to age because it's a strong beer and ALL strong beers need time to age.

 

[IslandLizard]

Was it 85 degrees the WHOLE time it was fermenting? If you got the temps down to something reasonable within 24-48 hours of pitching, then I bet everything is fine. You might have a perfectly wonderful beer that just needs a little time to age because it's a strong beer and ALL strong beers need time to age.

+1^

Strong beers benefit from (long term) aging, a few months to a year is common, sometimes it needs up to 2 years.

If you truly have fusel alcohols, due to high fermentation temps, your beer will taste harsh, aside from booziness. You'll need to learn to recognize the difference by taste and smell. Smell some rubbing alcohol or solvent alcohol for reference. If you taste those in your beer as well as nail polish remover (acetone), you've got fusels, and oxidation.

Aging will blend flavors and aromas and the booziness integrates nicely becoming smoother, while some of the fusel alcohols can be effectively masked, or perhaps oxidized away. But it can't cure everything.

But if you do indeed have a fusel bomb, there is not much you can do to fix it. You can cook with it. I often use strong beer for reduction sauces. Most of the alcohols are driven off during the reduction.

What was the fermentation temp, what yeast did you use? What is the alcohol % roughly?

 

[mwsenoj]

What was the fermentation temp, what yeast did you use? What is the alcohol % roughly?

68° using safale English ale yeast. Roughly 8% abv

Anyone willing to try a bottle if I mail it to you? There are no homebrew competitions here in the desert where I live so I don't have any experienced brewers/tasters to check locally.

 

[IJesusChrist]

68° using safale English ale yeast. Roughly 8% abv

Anyone willing to try a bottle if I mail it to you? There are no homebrew competitions here in the desert where I live so I don't have any experienced brewers/tasters to check locally.

Sure, I'm from Riverside, CA

 

[boydster]

68° using safale English ale yeast. Roughly 8% abv

Anyone willing to try a bottle if I mail it to you? There are no homebrew competitions here in the desert where I live so I don't have any experienced brewers/tasters to check locally.

I'd be willing to try one too, although IJesusChrist is much closer to you.