i am (obviously) new to this, so a basic question please. if i was to use my corny keg for secondary fermentation, how do you purge the O2 from the beer to safely open it to add, say, dry hops? can i just hook up the CO2, dial up a low pressure (say 5psi) for a few minutes, take off the gas and burp it a few times and done deal? safe to open without oxygenation worries?
edit: and i guess in a related note, should i just be doing this with ALL beers kept in a corny to ferment to purge the O2 from the headspace?