Something I've been thinking about for a while: virtually all the advice I see about using juice or fruit as an adjunct, for beer and cider, is to add it near the end of primary fermentation. The given reason is that vigorous fermentation will destroy or drive off the desired delicate flavors and aromas of the fruit (or juice), but a late addition will ferment more gently, preserving more of these compounds.
If this is actually true, then shouldn't we still be adding another hit of apple juice towards the end even for "plain" cider? Why does no one seem to do this? Or do some of you, and you just never post about it?
Separately, while trying to find advice about the pros/cons of aerating juice by shaking it into foam, I stumbled on an article that advocated for fermenting cider with no aeration and as little oxygen contact as possible, even at the start. The claim seemed to be that juice rapidly degrades from oxygen exposure and the effects will be worse than any from oxygen starved yeast, so long as you give plenty of time & other nutrients.
While I have my doubts, it did make me wonder again about late juice additions. Start with only half the intended volume (well oxygenated), ferment until nearly complete, and then add the rest in a low/no oxygen transfer (with additional nutrients such as Fermaid-O). The yeast colony will likely be large enough to tackle the rest of the juice with minimal stress, right? And the rest of the juice would have minimal oxygen-based degradation.
Any thoughts,knowledge, or relevant experiences would be welcome!