EXTRA OXYGENATION

[Lele]

Chris White says that is better to oxygenate high gravity beers after 12 h after pitch yeast. But then my airock often show me that fermentation has already begun. When do you do an extra oxygenation?

 

[HTH1975]

In a big beer, you can oxygenate again even if you’re actively seeing airlock activity. The thinking is that the fermentation will scavenge additional the CO2.

 

[mongoose33]

I believe what he's saying is to oxygenate again at 12 hours; you should also oxygenate at pitch.

 

[Lele]

In a big beer, you can oxygenate again even if you’re actively seeing airlock activity. The thinking is that the fermentation will scavenge additional the CO2.

Thanks
Just another question: if for example I oxygenate the wort before pitching yeast for 60 seconds, how many seconds do I have to oxygenate 12h after pitching?

 

[mongoose33]

Thanks
Just another question: if for example I oxygenate the wort before pitching yeast for 60 seconds, how many seconds do I have to oxygenate 12h after pitching?

I can't give you an authoritative answer as if I were Chris White, but I can tell you that, from what he says, "the addition of oxygen (some say more than 7ppm, some say more than 12ppm), at 12 hours increases fermentation speed by 33 percent and decreases flavor compounds such as diacetyl and acetaldehyde..." (Page 84 in YEAST).

He also says earlier in the book (page 64-65 I think) that the 12-hour oxygenation helps the yeast build reserves to get them to the end of fermentation, to allow full attenuation.

Look at me, almost as knowledgeable as Chris White!

BTW, if you don't have the YEAST book, get it; I can't recommend it enough.

PS: The YEAST book is co-authored by Jamil Zainasheff, so when I say "Chris White says this..." it's actually a duet.