Stuck fermentation. Emailed White Labs. Add O2?!?

[worldzfree]

Long story short, I am using WLP007 (a heavy flocculating yeast) on a 1.071 OG beer. At around 1.022 I transferred (in hindsight too early) to secondary to start dry hopping. It has been two weeks and it is now sitting at 1.020. It's too sweat for my liking. I emailed White Labs and had a dialog going with one of their lab specialists on how to get this ferment going again. I mentioned that I would get another vial of 007 and stir plate it in 1L of wort and then repitch at high kraussen. Here's the interesting part.

They recommended I give the almost two week fermenting a beer a blast of O2 as well as pitching the fresh starter.

me: wow! i had never heard that was an acceptable option. has the belief within the industry changed that there is no real adverse effect of reintroducing O2 into a beer that has been fermenting (almost) two weeks now?

white labs: That not really an industry belief, but more of a homebrew myth. I advise people all the time to rouse their yeast with O2 with stuck fermentations.

So that's where I am at. I have never heard of this before. While I each time I go to a yeast talk from either White Labs or Wyeast I get more and more reality checks on how yeast works and what is homebrew lore this is a big one. Beyond everyone responding, "this will oxidize your beer!", I am also curious as to whether anyone else has tried this and actually tasted the beer to see if the whole oxidization/wet cardboard flavor belief is strongly based on myth.

I ended up introducing O2 at 1lpm through a .5 micron stone for roughly 30 seconds (I chickened out on their 1 to 2 minute recommendation) to see what happens. I will report back my results.

 

[BryceL]

I've never added O2 to fermenting beer, never really had the need to and personally wouldn't want to. Depending on your mash temp our if you are using extract, you could be at your FG. Your at 72% attenuation right now and I see 007 is rated at 70-80. I be curious to hear your results though.

 

[worldzfree]

It was a 150 rest. All-grain. 85% 2-row, 10% white wheat, 5% crystal 20. I realize it is in their attenuation range but I typically get in the low to mid teens on a beer of this sort.

 

[Yooper]

I've never added O2 to fermenting beer, never really had the need to and personally wouldn't want to. Depending on your mash temp our if you are using extract, you could be at your FG. Your at 72% attenuation right now and I see 007 is rated at 70-80. I be curious to hear your results though.

Yes, I guess that's what I was thinking. I'd have no calms adding 02 to a truly stuck fermentation (and I stir my wines when fermenting, down to 1.010 or so).

But for an underpitched 1.071 beer, I'd be less inclined to consider this stuck, and more inclined to call it done.

I'm surprised White Labs would expect a higher attenuation % than their lowest average listed. I calculate the attenuation currently at 70.5%. Their website states 70-80% as the average attenuation. Sure, that's on the low end, but certainly within range. That really does surprise me. I think it'd be one thing if you got 63% attenuation and then called it stuck. I know many times that yeast can go higher, but with the underpitching I wouldn't expect much above 72-75% anyway.

I'm looking forward to seeing how the beer comes out- both the FG and the flavor!