Originally Posted by butterpants
You don't think that racking and adding those 2 compounds would arrest fermentation with the carboy at 65F? Man I sure figured it would.
I guess it could be stress funk.... don't know
Campden doesn't do anything to wine yeast- that's why winemakers use it as an antioxidant. It will stun/slow wine yeast in HUGE amounts, but the cider would have to have something like 150-200 ppm for that to happen.
Sorbate doesn't kill yeast, either- but it does inhibit yeast reproduction. That's why it works in a finished wine or cider, once it's clear. The yeast would fall out and be racked off and once the wine is clear, sorbate is added. There are still yeast present, but they can't reproduce so they don't restart fermentation.
By adding it to an active fermentation, it won't do anything much since the yeast have already reproduced and are already fermenting. There should be plenty of yeast in suspension to ferment, since the yeast's reproductive phase was long finished.
If the cider was very clear, though, and it was nearly done, it's possible that adding the sorbate would slow it enough. I have a feeling that it wasn't nearly done at 1.017, but I might very well be wrong (and I hope I am!).
The thing that most likely happened is that the yeast got stressed, and that will cause "rhino farts" types of aromas. If you could possibly get the cider cold, that would help stall the yeast enough that the sorbate could possibly be effective.