This is my first time making cider. I got 6 gal of orchard-fresh cider and let sit since October. I just moved to a secondary to let sit for a bit longer (after 3 months). I added some sugar and it fizzed all over. Now the cider is completely still (three days later). Can I still make this a sparkling cider when I bottle it? Should I bottle it now? Is the yeast dead?