Oxygenation help

Last night I had my lager chilled to 50F so I pitched my yeast (2 pkgs. of 34/70, rehydrated and at the same temp as the wort) and oxygenated. I use the red tanks and a sintered stone, normally 2 x 30 second applications for an ale. For this lager I pitched more yeast and the wort is colder so I was planning on 4 x 30 second applications. However, my tank ran dry after about 2 blasts and I can't be sure how good the second one was.

Today I finally managed to find a hardware store with another tank so I could add more O2 now. So, is it too late to add O2? I pitched last night at 9:30 and it's 3:00pm here right now so it's been almost 18 hours. There is no visible activity yet but I'm not worried about that. I'm just concerned that adding O2 at this point would do more harm than good.

Any advice is greatly appreciated.

Cheers!
Kevin in Essex

Go ahead and add the extra O2. I've done 120 seconds on day 2 for a huge doppelbock and it turned out great. Given your low temps I wouldn't think twice about it--your yeast are cold and will appreciate the help!

I've not heard of people doing so many multiple O2 infusions for a batch, but if it works for you that's great. I usually do 1 x 60, 90 or 120 seconds depending on the beer. For very big lagers fermenting cool I might do a second infusion on day 2.

Thanks for the help.

Cheers!