Topping off

I've seen some mention of topping off the secondary with more juice after racking to fill space. Two questions:

a) Is that standard/common for any of you?

b) If I used apple juice with preservatives, would that also act as a sweetener without activating further fermentation? Or, more generally, can apple juice with preservatives be used to backsweeten cider?

do not use juice with preservatives, as that will kill fermentation completely. you could add juice after racking, but i never have, and yes, it would be to just add more bulk

I do it. I also add juice every time I take a gravity sample. Non-preservative. The Preservatives will kill the yeast.

Does anybody have any experience with adding juice with preservatives actually killing the yeast? If it can actually kill a healthy, active fermentation then this might be another option for stopping a fermentation at the desired sweetness.

I suspect that the preservatives will act a lot like potassium metabisulfite/potassium sorbate and prevent yeast replication, but won't actually halt an active fermentation.

Anybody a) tried or b) know the science?

Cheers

HW

Funny you asked this. I was thinking the same thing.
Even if it slows down bottle carbing a bit it might make it easier to pasteurize when the carb is right and not create bombs.

I doubt adding a cup of store/preservative juice to 5 gallons of fermenting cider would stop fermentation or do much more than pose a minor annoyance to the yeast.

Even a 50/50 mix of your fermenting batch + store juice - counting on the preservatives in that juice is still a dicey proposition.... Though it would be a cheap way to do it if it worked out.... so it is probably worth a try just to see what happens...

Remember - that preservative is there to stop a small amount of residual yeast/bacteria from kicking over inside the sealed bottle at the store and spoiling it while it's on the shelf.... It will still go bad if you let it sit open on your counter top for more than a few days....

Thanks