Purging O2 from Secondary with Corn Sugar

[PDonn63]

So I've got an amber ale thats been three weeks in the secondary. I just harvested about .75 oz (dry) cascade hops from a first year plant and decided I just want to dry hop this batch rather than bother with packaging this small amount of hops. However, I'm curious about what the beer would taste like without the dry hop addition, so I will pop the airlock, bottle a six packs worth, add the hops to whats left (~4.5 gallons), and reattach the airlock for a few more days before kegging the rest.

I have to imagine though, that a fair amount of O2 would make its way in to the carboy with the airlock being off for this long. Would adding a few tablespoons of Corn Sugar cause enough renewed fermentation to purge the O2 and provide a nice blanket of CO2? I figure it'd be like priming a bottle but scaled up, right? Only no carbonation because of the airlocks pressure release.

 

[DrawTap88]

That would work. But adding the hops to the secondary will knock enouch CO2 out of solution to create the blanket. Adding the corn sugar and restarting fermentation could push out more hop flavor than it's worth.

 

[RainyDay]

I wouldnt worry about the CO2 if you're just taking the airlock off and adding something/taking a sample/whatever. Now if you shake the crap out of the carboy, then its a different story.