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?
If you’re just using air and not pure O2, the maximum saturation you can achieve regardless of the method is ~8ppm O2, so it’s not possible to put too much O2 in the wort (as long as you’re doing this within 24 hours of pitching the yeast).
If you have oxidation problems, look at your post fermentation handling practices, particularly your transfers.
I think I’m struggling with this as well. My problem is that it tastes oxidized coming out of primary, before racking. ?? I use pure o2 and the only other variable I can think of is that I used crushed grains that were a few months old. I thought that would have just lowered my effeciency?
I’m curious if you made a starter?
One batch was done with properly rehydrated dry yeast and the other was pitched with yeast harvested from another fermenting brew (which turned out fine) about two days before. Both fermentations took off quickly and proceeded normally. Both batches were left in the primary for 3-4 weeks before bottling. Transfer to the bottling bucket was done with my usual minimal splashing. Bottling went as always…same water as always.
One batch was dried malt extract with some crystal malt and the other was all grain. The ingredients for both batches smelled and tasted fine.
I’m really at a loss to explain this…
I read, heard, maybe I’m making it up, that yeast only use oxygen for splitting, not consuming. So if we’re pitching the proper amount (sounds like in both cases you are) perhaps all the o2 is staying in there? I don’t know if 8ppm is enough to oxidize, even if left in there and unused by the yeast.
