successfully jumpstarting a stuck fermentation with pure O2

[dmarc85]

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[dmarc85]

Wow, this thread has quickly turned into the refractometer debate forum!

OP please post your findings as I didn't think it was ok to add additional oxygen to the partially fermented beer once you were past 24 hours or so as it would oxidize the beer. I've heard of adding some sugar and gently stirring the wort/beer beyond 24 hours to arouse the yeast but never adding more oxygen.

So nearly two weeks after I first pitched yeast, I took a risk and added o2 to a big beer that I suspected had a stuck fermentation due to lack of oxygen.

A good fermentation kicked back up within 8 hours of adding a 20 sec burst of oxygen to ~17 gallons of beer with a deeply submerged aeration stone. I saw my ferm temp rise from ambient temp to about +4F above the ambient temp. The rapid fermentation subsided after 24 hrs. I took a peek inside my fermenter last night and noticed a small krausen present with bubbling rapidly rising to the surface.

NOTE: Just 24 hrs after adding oxygen, I pulled a sample and took a hydro reading (1.015). I imagine that my current gravity I now below 1.010. I chilled and drank the beer that I pulled for a reading, which was 22oz . Aside from having all the strange flavors of a flat beer that has not been aged at all. I did not notice any tell-tale smells or flavored of oxidation. This beer is definitely pushing 9-10% ABV now; I put the whole 22oz down on an empty stomach after work and I was running into walls on the way to bed

 

[peterj]

So nearly two weeks after I first pitched yeast, I took a risk and added o2 to a big beer that I suspected had a stuck fermentation due to lack of oxygen.

A good fermentation kicked back up within 8 hours of adding a 20 sec burst of oxygen to ~17 gallons of beer with a deeply submerged aeration stone. I saw my ferm temp rise from ambient temp to about +4F above the ambient temp. The rapid fermentation subsided after 24 hrs. I took a peek inside my fermenter last night and noticed a small krausen present with bubbling rapidly rising to the surface.

NOTE: Just 24 hrs after adding oxygen, I pulled a sample and took a hydro reading (1.015). I imagine that my current gravity I now below 1.010. I chilled and drank the beer that I pulled for a reading, which was 22oz . Aside from having all the strange flavors of a flat beer that has not been aged at all. I did not notice any tell-tale smells or flavored of oxidation. This beer is definitely pushing 9-10% ABV now; I put the whole 22oz down on an empty stomach after work and I was running into walls on the way to bed

You pulled 22 ounces off to take a hydrometer reading? Seems like a lot, but I guess if you enjoyed drinking it then it's not really a waste!

Also I think it's going to take a little while for the oxidation to become evident. I believe it's a chemical reaction that takes place over time where the oxygen binds to either esters or alcohol or maybe both. Not exactly sure, but I know that it takes a while to develop. So if you down this batch quickly, you might not ever have to find out if it would have become oxidized!

Though since you had a restart to fermentation, the yeast may have gobbled up all the free oxygen you added. So that's a good sign as well! Good luck!

 

[dmarc85]

I lost my graduated cylinder so I used a wine bottle to get the hydrometer reading. Haha. It probably the best time I've had taking a gravity reading.

I'll keep this thread updated on my brew.


Sent from my iPhone using Home Brew

 

[dmarc85]

Took a sample last night (12oz) and I was impressed! Not only was the flavor clean, but the large percentage of dextrose left my beer tasting more like a 5%ABV beer, with a subtle aftertaste of alcohol, reminiscent of a barley wine without the sweetness. I imagine this final product finished about 10%ABV; I was pretty drunk after I finished it (granted I had about 64oz of Rogue coursing through my system already.

I've oxidized homebrew before, so I know what to look for...this beer is clean.

 

[trentm]

Took a sample last night (12oz) and I was impressed! Not only was the flavor clean, but the large percentage of dextrose left my beer tasting more like a 5%ABV beer, with a subtle aftertaste of alcohol, reminiscent of a barley wine without the sweetness. I imagine this final product finished about 10%ABV; I was pretty drunk after I finished it (granted I had about 64oz of Rogue coursing through my system already.

I've oxidized homebrew before, so I know what to look for...this beer is clean.

Thanks for the OP and the updates. A lot of people would not have had the pluck to try this and if so would not have posted it . An earlier post suggested you drink this before it has time for oxydation. Which may be good advice but please try to keep some around for evaluation. I would really like to know if oxidation develops over time.

 

[dmarc85]

I certainly will keep the updates coming. I've still got +15gals left so more testing and final products shouldn't be a problem.

 

[dmarc85]

I'm on my 3rd pint. I don't detect any signs of oxidation. I think I'm in the clear. This batch has gone to the keg and will age a bit before sharing.


My original beer must have certainly been starved of oxygen as I suspected. Lucky I say. one thing is for sure; I'm getting drunk

 

[doug293cz]

I'm on my 3rd pint. I don't detect any signs of oxidation. I think I'm in the clear. This batch has gone to the keg and will age a bit before sharing.

My original beer must have certainly been starved of oxygen as I suspected. Lucky I say. one thing is for sure; I'm getting drunk

Thanks for reporting on this unintentional experiment. I for one, would not have dared to try oxygenation so long after pitching. Nice to know that it can be used if necessary.

Brew on

 

[dmarc85]

Thanks for the OP and the updates. A lot of people would not have had the pluck to try this and if so would not have posted it . An earlier post suggested you drink this before it has time for oxydation. Which may be good advice but please try to keep some around for evaluation. I would really like to know if oxidation develops over time.

Its been 2 months since brewday and the beer is still clean. Its actually getting better with time, which is to be expected with a big beer.

My conclusions...adding o2 late in the game worked, but that was only because I had so many unfermented sugars left over after the first yeast petered out. It should be noted that this beer was accidentally mashed just below 170F, stupid herms coil! The final flavor is very malty and bold.

 

[trentm]

Impressive. Thanks for the update.