I made a cider recently that I allowed to ferment out to 1.000. Now it's time to keg and I want to backsweeten, with apple juice concentrate. I don't have any access to potassium sorbate, and won't for a few days. However I want to get the cider in a keg and hopefully have it partially carbed by thanksgiving. If I keep the keg chilled around 40!F will the yeast continue to ferment? I used dry champagne yeast, I think danstar. Also can I add potassium sorbate later when I can get my hands on some?