So, I was running off the wort into the boil kettle, and after a while i noticed tons of air bubbles in the line running from the tun to the kettle. I took me until the second run until i realized the problem. The barb fitting connecting into the ball valve on my cooler was too loose and was allowing air into the line--I have never had this happen. So how bad did I oxidize my wort? I went through a full run and half of my second run (I batch sparge) before correcting the problem.