No chiller method with a keg?

[unfairbeef]

I posted this as a comment in a thread about chilling wort but figured I should have posted it as a thread and not in the already existing (sort of a different topic) thread since it was so long-winded:

So, looking at the Aussie method of doing this, anyone see any problems with me using a keg to do the 'no chill' method? The only issue I think I might run into is that the keg is 7.5 gallons and I would be putting 7 gallons into it, leaving a bit of headspace (read: oxygen). I am thinking that the still incredibly hot wort will sterilize everything in the keg, I can then toss it in the empty kegerator after it has cooled a bit as to not damage the kegerator. That will let me start my fermentation kinda low and let it rise naturally during fermentation, rack it into the 7.5 gallon bucket to clean the trub out of the keg, then rack it right back into the keg, drop a hop bag in there and hook up the co2. I suppose tossing in the prescribed amount of priming sugar and seal up the keg, leaving it out of the kegerator for another few days or so then cold crash it. Any thoughts on this? Any obvious flaws that you see? Thanks!

Referenced Method

 

[Prymal]

You could always purge the oxygen out with a little CO2 while it is still hot that way there is no o2 in the head space while it cools down if you are worried. But since this is Pre-Fermentation Oxygen isnt really much of an issue. You want oxygen in your wort before you pitch the yeast and the hot air circulating from the cooling of the wort should be enough to kill off any bacteria that might be present. I say give it a try and find out if it works. I am now thinking about the one downside. The seals on the keg are not ment for High Temps so maybe have a spare set of seals on hand to replace between cooling the wort and serving the beer.

 

[unfairbeef]

I am thinking that I won't even have the spear in the (sanke 1/4 barrel slim) keg (and therefore none of the aforementioned seals). I may just cover it with rubber-banded paper towels that have sanitizer on them. Then once it cools off, stick the carboy cap and an airlock on it. I realize there error in my thoughts about the oxygen, too; I guess I was most concerned about bacteria in the air but then again, that's pretty much the same thing as doing it in a carboy.