My friend and I pressed some apples to make a hard cider back in August. When we racked that cider we didn't want to waste the yeast, so I went out and bought some juice. Unfortunately all I could find had potassium sorbate, but I figured I'd give it a shot for a few bucks and see if the yeast could overcome.
It seemed to start fermentation for a few days, but then went dead for 2 weeks. Last week it started back up and it seems like I've got a very slow fermentation going now (about 4 bubbles through the airlock per minute).
Now that apple season is fully underway I'd like to get some more juice without sorbate or press some apples and pour it over the old yeast. Can I rack off this current sorbate cider and pour some new juice on top of the old yeast now, or will I be disrupting my fermentation too much?