Sorry, I was combining thoughts and maybe should not have thrown in that hot side mention. So it's just about the mash? I thought it was important to be gentle with the whirlpool too? I swirl it every 5 minutes.
I have a 40 minute hop stand and whirlpool for my NEIPA starting at 175, so in theory that could introduce oxygen. But maybe that really doesn't matter?
The oxidation seems to be coming more from the cold side, especially the transfer to secondary, but also in the bottling bucket.
No, it's not just the mash. To really do this according to LODO doctrine, you need to deoxygenate the strike water, eliminate copper, purge the lines if you're recirculating, use a mash cap (to prevent exposure of the mash to atmospheric oxygen as much as possible), add some K-meta or P-meta as an o2 scavenger (campden tablets work, I use 1.5 of them, crushed), avoid splashing if you stir, when you rack to the boil kettle use a lauter cap (same idea as mash cap).
The idea on the hot side is to prevent oxidation from destroying malt flavors. Once the boil is complete, there should be no oxygen in the wort--it's been driven off by the boiling. While you may get some while whirlpooling or a hop stand, it depends on how hot the wort is. The hotter it is, the less O2 it can absorb.
I've been diddling with LODO now for almost a year; it's got a lot of moving parts, it's a fiddly thing. In the end, one must decide if the result is worth it. Come to find out that some people are very sensitive to oxidation of the malt flavors, others not so much.
I've had enough success to know there's something there. I've brewed a couple of Pils whose flavors were just stunningly up front--in fact, almost so much that I had to decide if I liked it. I have a friend with a great palate who's my go-to for seeing if he can pick up off-flavors in my beers, he was most complimentary of the pils.
As for me...I didn't really like it all that much. I drank it, but there are other beers I'd rather have. That said, I've done an Amber using LODO techniques that knocked my socks off. Haven't been able to reproduce the damned thing, either. Close, but the socks stayed on.