I’ve had two batches in a row that taste oxidized after they’ve carbonated in the bottles. The only difference between these batches and my previous 50 or 60 was that I used a (sanitized) paint mixer in an electric drill to oxgenate the wort before pitching the yeast (previoulsy I just used the old pour and shake method). The wort temp at the time of oxygenation was below 70 degrees. I mixed the heck out of the wort causing a huge head to form, let it settle and mixed it up again - maybe a total mix time of 10 mins.
So, my questions are am I over-oxygenating the cooled wort before pitching the yeast and is this the likely cause of my oxidation problem in the finished beer?